The addition of high-content crumb rubber(HCCR)in asphalt can effectively address waste tire pollution and provide sustainable environmental and economic advantages.However,the practical application of conventional ru...The addition of high-content crumb rubber(HCCR)in asphalt can effectively address waste tire pollution and provide sustainable environmental and economic advantages.However,the practical application of conventional rubberized binders is significantly limited by high viscosity and poor storage stability.To address these issues,researchers have pretreated crumb rubber(CR)with oil,but high-temperature performance remains insufficient.Therefore,this study aimed to optimize the viscosity,storage stability,and rheological properties of high-content crumb rubber-modified asphalt(HCCRMA)by varying the pretreatment levels of CR and incorporating various additives,including styrene-butadiene-styrene(SBS),deoiled asphalt(DA),or recycled low-density polyethylene(RLDPE).In addition,CR was pretreated with waste cooking oil(WCO)at various ratios,pre-swelling temperatures,and times.The results show that DA exhibits excellent storage stability and lower viscosity compared with other modifiers in HCCRMA,and the 4%RLDPE with pretreated HCCR has the greatest high-temperature rutting resistance.The inclusion of RLDPE increases the stiffness and elasticity of the modified asphalt,which results in greater high-temperature performance.Additionally,the fluorescence microscopy(FM)test confirms that SBS exhibits better dispersion than other modifiers and forms a more homogeneous phase separation in the HCCRMA.All in all,this research achieved an optimal balance of storage stability and rheological properties in asphalt modified with pretreated HCCR and 6%SBS,which provides a valuable reference for performance improvement of HCCR-modified binders.展开更多
Recycling of waste rubber(WR)is crucial for the sustainable development of the rubber industry.The enhancement of interfacial interactions is the main strategy for waste polymer recycling.However,there is a lack of me...Recycling of waste rubber(WR)is crucial for the sustainable development of the rubber industry.The enhancement of interfacial interactions is the main strategy for waste polymer recycling.However,there is a lack of methods for enhancing the interfacial interactions for WR recycling because WR contains abundant inert C―H bonds.Herein,we designed thioctic acid inverse vulcanization copolymers to endow recycled WR with dynamic disulfide interfacial interactions,significantly improving the mechanical properties of recycled WR.These disulfide interfacial interactions among the recycled WR tend to exchange,which dramatically increases the fractocohesive length and prevents stress concentration near the crack tips.When recycled WR is subjected to external stress,the loads are redistributed across a broad region of adjacent regions instead of being concentrated on a limited length scale,which resists crack propagation.This work effectively recycled WR,providing a strategy for solvent-free reaction-derived inverse vulcanization copolymers to improve the toughness of WR recycling.展开更多
This study investigates the potential of starch extracted from underutilized agro-industrial resources as non-food-competing raw materials for the development of flexible bioplastics for food packaging applications.St...This study investigates the potential of starch extracted from underutilized agro-industrial resources as non-food-competing raw materials for the development of flexible bioplastics for food packaging applications.Starch was extracted from three biomass sources:rubber cassava(Manihot glaziovii),banana stem,and banana peel from Ambonese banana(Musa acuminata L.).Rubber cassava starch(SRC)exhibited the highest starch yield(50.68±0.28%),significantly surpassing banana stem(SBS,14.20±0.25%)and banana peel(SBP,3.07±0.15%).The amylose contents of SRC,SBS,and SBP were 28.18%,52.80%,and 56.57%,respectively,while their amylopectin contents were 71.83%,47.20%,and 43.43%.FTIR spectra confirmed the absence of cyanogenic groups in SRC,indicating its safety for packaging applications.XRD analysis revealed that PSRC films were predominantly amorphous,while PSBS and PSBP showed higher crystallinity.The enhancement of mechanical properties,specifically PSBS,showed the highest tensile strength at 16.04±0.56 MPa,whereas PSRC demonstrated the highest elongation at break at 23.57±0.40%,which could be attributed to the inherent characteristics of the starch sources.Additionally,PSRC film exhibited the highest transparency at 60.2%,the greatest water solubility at 34.92%,and the lowest water contact angle at 41.58○,confirming its more hydrophilic nature compared to other films.This work highlights the potential of low-cost,sustainable,and non-food agro-industrial starch sources as promising candidates for the development of flexible,eco-friendly bioplastics.展开更多
The glass transition temperature(T_(g))of styrene-butadiene rubber(SBR)is a key parameter determining its low-temperature flexibility and processing performance.Accurate prediction of T_(g)is crucial formaterial desig...The glass transition temperature(T_(g))of styrene-butadiene rubber(SBR)is a key parameter determining its low-temperature flexibility and processing performance.Accurate prediction of T_(g)is crucial formaterial design and application optimisation.Addressing the limitations of traditional experimental measurements and theoretical models in terms of efficiency,cost,and accuracy,this study proposes a machine learning prediction framework that integrates multi-model ensemble and Bayesian optimization by constructing a multi-component feature dataset and algorithm optimization strategy.Based on the constructed high-quality dataset containing 96 SBR samples,ninemachine learning models were employed to predict the T_(g)of SBR and compare their prediction performance.Ultimately,aGPR-XGBoost mixed model was constructed through model ensemble,achieving high-precision prediction with R^(2)values greater than 0.9 on both the training and test sets.Further feature attribution and local effect analysis were conducted using feature analysis methods such as SHAP and ALE,revealing the nonlinear influence patterns of various components on T_(g),providing a theoretical basis for SBR formulation design and T_(g)regulation.The machine learning prediction framework established in this study combines high-precision prediction with interpretability,significantly enhancing the prediction performance of the T_(g)of SBR.It offers an efficient tool for SBR molecular design and holds great potential for promotion and application.展开更多
The flocculation behavior of carbon black (CB)-filled isoprene rubber (IR) nanocomposites was systematically investigated under both dynamic and static conditions to unravel the distinct mechanisms governing filler ne...The flocculation behavior of carbon black (CB)-filled isoprene rubber (IR) nanocomposites was systematically investigated under both dynamic and static conditions to unravel the distinct mechanisms governing filler network evolution.Under dynamic conditions,small oscillatory shear strains (0.1%) significantly enhanced filler particle motion,leading to pronounced agglomeration and a flocculation degree of about 4.3MPa at 145℃.In contrast,static flocculation exhibited a fundamentally different mechanism dominated by polymer chain dynamics,which is driven mainly by thermal activation.Radial distribution function (RDF) analysis of transmission electron microscopy (TEM) images revealed a slight decrease (2 nm) in the interparticle distance peak after static annealing at 100℃ for 7 h,indicating localized motion of CB particles.However,the overall filler network remained stable,with no significant agglomeration observed.The increase in bound rubber content from about 23% to 28% with rising temperature further confirmed the dominant role of polymer chain adsorption and interfacial reinforcement in static flocculation.These findings highlight the critical influence of external strain on filler network formation and provide new insights into the polymer-dominated mechanism of static flocculation.The results offer practical guidance for optimizing the storage and processing of rubber nanocomposites,particularly in applications where static flocculation during prolonged storage is a concern.展开更多
Immunosuppressed patients have increased susceptibility to various infections,including opportunistic infections.The risk of infective complications in these patients is significantly higher,which can lead to more sev...Immunosuppressed patients have increased susceptibility to various infections,including opportunistic infections.The risk of infective complications in these patients is significantly higher,which can lead to more severe infections,prolonged illness course,and an increased likelihood of poor outcome,including sepsis,organ failure,and even death.Blue rubber bleb nevus syndrome(BRBNS)is a rare syndrome characterized by venous malformations primarily found in the skin and gastrointestinal(GI)tract.展开更多
Natural rubber(NR)is a crucial elastic material used for damping and sealing applications in the nuclear industry,but its mechanical stability under radiation remains inadequate.Current efforts to improve radiation re...Natural rubber(NR)is a crucial elastic material used for damping and sealing applications in the nuclear industry,but its mechanical stability under radiation remains inadequate.Current efforts to improve radiation resistance rely on the addition of antiradiation agents,however,the effects of the components and microstructures of NR itself on radiation resistance remain unclear.In this study,we compared the composition and structure differences of four typical commercially used NR materials and investigated their effects on gamma radiation resistance.Furthermore,we examined the impact of non-rubber components(NRC)in NR on radiation resistance using deproteinized and dephosphorylated NR model samples.Our results revealed that NRC,such as proteins and phospholipids can enhance the strength of natural rubber before radiation exposure.However,after the removal of NRC,the samples exhibited improved mechanical stability under irradiation.Additionally,the ash content in NR could also influence the radiation resistance,as metal ions may react with the active centers produced by radiation,thereby enhancing the radiation resistance of the rubber.This work identifies the effect of non-rubber components in NR on radiation resistance and may serve as a reference for screening and developing radiation-resistant NR materials.展开更多
Herein,cure characteristics,morphology,and mechanical properties of natural rubber filled with activated carbon-based materials were investigated.Carbon-based materials were prepared from bagasse,coffee grounds and pi...Herein,cure characteristics,morphology,and mechanical properties of natural rubber filled with activated carbon-based materials were investigated.Carbon-based materials were prepared from bagasse,coffee grounds and pineapple crowns by the pyrolysis method at temperatures in the range of 300℃.As-synthesized carbon materials were characterized by optical microscopy(OM),scanning electron microscopy(SEM),and Fourier-transform infrared spectroscopy(FTIR)to analyze size distribution,morphology,and functional groups,respectively.OM and SEM analysis revealed that particles,flakes,and a small quantity of fiber-like carbon were obtained using bagasse and pineapple crown as raw materials,while honeycomb-like carbon materials can be derived from coffee grounds.To investigate the mechanical properties,natural rubber was filled with carbon black and as-synthesized carbon materials by the internal mixing and compression molding process.Transmission electron microscopy(TEM)was utilized to characterize the dispersion of carbon materials in the rubber matrix.The results of tensile testing showed that the natural rubber mixed with as-synthesized carbon materials from pineapple crowns exhibited 54%and 74%improvement in the ultimate tensile strength and Young’s modulus,respectively,compared with natural rubber without filled carbon materials.The enhancement in mechanical properties by activated carbon materials derived from pineapple crowns can be attributed to the flake-and fiber-like structures and good dispersion of carbon materials in the rubber matrix.In addition,it is higher than that of rubber mixed with carbon black.The results demonstrated that as-synthesized carbon materials from pineapple crowns have the potential materials to substitute carbon black in the rubber compound industry.展开更多
Purpose–The brake pipe system was an essential braking component of the railway freight trains,but the existing E-type sealing rings had problems such as insufficient low-temperature resistance,poor heat stability an...Purpose–The brake pipe system was an essential braking component of the railway freight trains,but the existing E-type sealing rings had problems such as insufficient low-temperature resistance,poor heat stability and short service life.To address these issues,low-phenyl silicone rubber was prepared and tested,and the finite element analysis and experimental studies on the sealing performance of its sealing rings were carried out.Design/methodology/approach–The low-temperature resistance and thermal stability of the prepared lowphenyl silicone rubber were studied using low-temperature tensile testing,differential scanning calorimetry,dynamic thermomechanical analysis and thermogravimetric analysis.The sealing performance of the lowphenyl silicone rubber sealing ring was studied by using finite element analysis software abaqus and experiments.Findings–The prepared low-phenyl silicone rubber sealing ring possessed excellent low-temperature resistance and thermal stability.According to the finite element analysis results,the finish of the flange sealing surface and groove outer edge should be ensured,and extrusion damage should be avoided.The sealing rings were more susceptible to damage in high compression ratio and/or low-temperature environments.When the sealing effect was ensured,a small compression ratio should be selected,and rubbers with hardness and elasticity less affected by temperature should be selected.The prepared low-phenyl silicone rubber sealing ring had zero leakage at both room temperature(RT)and�508C.Originality/value–The innovation of this study is that it provides valuable data and experience for the future development of the sealing rings used in the brake pipe flange joints of the railway freight cars in China.展开更多
This review provides a comprehensive overview of natural rubber(NR)composites,focusing on their properties,compounding aspects,and renewable practices involving natural fibre reinforcement.The properties of NR are inf...This review provides a comprehensive overview of natural rubber(NR)composites,focusing on their properties,compounding aspects,and renewable practices involving natural fibre reinforcement.The properties of NR are influenced by the compounding process,which incorporates ingredients such as elastomers,vulcanizing agents,accelerators,activators,and fillers like carbon black and silica.While effective in enhancing properties,these fillers lack biodegradability,prompting the exploration of sustainable alternatives.The potential of natural fibres as renewable reinforcements in NR composites is thoroughly covered in this review,highlighting both their advan-tages,such as improved sustainability,and the challenges they present,such as compatibility with the rubber matrix.Surface treatment methods,including alkali and silane treatments,are also discussed as solutions to improve fibre-matrix adhesion and mitigate these challenges.Additionally,the review highlights the potential of oil palm empty fruit bunch(EFB)fibres as a natural fibre reinforcement.The abundance of EFB fibres and their alignment with sustainable practices make them promising substitutes for conventional fillers,contributing to valuable knowledge and supporting the broader move towards renewable reinforcement to improve sustain-ability without compromising the key properties of rubber composites.展开更多
Silicone rubber(SR)exhibits superior breathability and high-temperature resistance.However,SR is prone to degradation under extreme heat or combustion,limiting its effectiveness in mitigating secondary hazards.In this...Silicone rubber(SR)exhibits superior breathability and high-temperature resistance.However,SR is prone to degradation under extreme heat or combustion,limiting its effectiveness in mitigating secondary hazards.In this study,phosphate glass powder was used to calcinate zinc borate,lanthanum oxide,and cerium oxide.Methylphenyl polysiloxane was then grafted onto the surface of the glass powder,resulting in the modified pow-ders designated as Methylphenyl polysiloxane-grafted zinc borate-modified phosphate glass powder(GF-ZnBM),Methylphenyl polysiloxane-grafted lanthanum oxide-modified phosphate glass powder(GF-LaM),and Methylphenyl polysiloxane-grafted cerium oxide-modified phosphate glass powder(GF-CeM).The modified powders were sub-sequently incorporated into silicone rubber composites to enhance the ceramicization capability of silicone rubber at high temperatures.Specifically,GF-CeM and GF-LaM significantly increased the limiting oxygen index(LOI)to 33%and reduced the tendency for combustion propagation.Additionally,GF-CeM notably contributed to enhancing ceramicization strength.The presence of cerium oxide helps in the melting of the glass powder and enhances its adhesion to the silicone rubber matrix.SR/ZnB-GF exhibited the lowest activation energy among the tested composites,along with the best protective capability.The inclusion of modified glass powder has a minor impact on the rheological properties,indicating that the composite retains its ability to flow and deform under stress.This confirms that the material remains flexible under normal conditions and forms a ceramic structure when heated,thereby exhibiting self-supporting properties.This study provides a practical methodology for the targeted modification of glass powders,thereby further enhancing the fire safety of silicone-based composites.展开更多
Silicone rubber(SR)is a versatile material widely used across various advanced functional applications,such as soft actuators and robots,flexible electronics,and medical devices.However,most SR molding methods rely on...Silicone rubber(SR)is a versatile material widely used across various advanced functional applications,such as soft actuators and robots,flexible electronics,and medical devices.However,most SR molding methods rely on traditional thermal processing or direct ink writing three-dimensional(3D)printing.These methods are not conducive to manufacturing complex structures and present challenges such as time inefficiency,poor accuracy,and the necessity of multiple steps,significantly limiting SR applications.In this study,we developed an SR-based ink suitable for vat photopolymerization 3D printing using a multi-thiol monomer.This ink enables the one-step fabrication of complex architectures with high printing resolution at the micrometer scale,providing excellent mechanical strength and superior chemical stability.Specifically,the optimized 3D printing SR-20 exhibits a tensile stress of 1.96 MPa,an elongation at break of 487.9%,and an elastic modulus of 225.4 kPa.Additionally,the 3D-printed SR samples can withstand various solvents(acetone,toluene,and tetrahydrofuran)and endure temperatures ranging from-50℃ to 180℃,demonstrating superior stability.As a emonstration of the application,we successfully fabricated a series of SR-based soft pneumatic actuators and grippers in a single step with this technology,allowing for free assembly for the first time.This ultraviolet-curable SR,with high printing resolution and exceptional stability performance,has significant potential to enhance the capabilities of 3D printing for applications in soft actuators,robotics,flexible electronics,and medical devices.展开更多
The predictive model and design of heavy-duty metal rubber shock absorber for the powertrains of heavy-load mining vehicles were investigated.The microstructural characteristics of the wire mesh were elucidated using ...The predictive model and design of heavy-duty metal rubber shock absorber for the powertrains of heavy-load mining vehicles were investigated.The microstructural characteristics of the wire mesh were elucidated using fractal graphs.A numerical model based on virtual fabrication technique was established to propose a design scheme for the wire mesh component.Four sets of wire mesh shock absorbers with various relative densities were prepared and a predictive model based on these relative densities was established through mechanical testing.To further enhance the predictive accuracy,a variable transposition fitting method was proposed to refine the model.Residual analysis was employed to quantitatively validate the results against those obtained from an experimental control group.The results show that the improved model exhibits higher predictive accuracy than the original model,with the determination coefficient(R^(2))of 0.9624.This study provides theoretical support for designing wire mesh shock absorbers with reduced testing requirements and enhanced design efficiency.展开更多
Rubbery waste at the end of the cycle often constitutes a threat for the environment because of their encumbrance and low biodeterioration.The purpose of the research presented is to develop the rubber fine powder as ...Rubbery waste at the end of the cycle often constitutes a threat for the environment because of their encumbrance and low biodeterioration.The purpose of the research presented is to develop the rubber fine powder as a pavement.It is interested primarily in the behavior of two types of bitumen 40/50 modified by the addition of two varieties of rubber fine powders of different grading,resulting from the crushing of the rubbery products intended for the clothes industry of soles of shoes.The objective of the experimentation is to study the influence of the added polymer on the physical properties of the ordinary road bitumen with the incorporation of the fine powder.The experimental approach is carried out using the two tests of characterization of the bitumen i.e.the softening point test and the penetration test which remain the most used to define and classify the road bitumen.It will be noted however,that the experimental investigation which is based on several tests according to the type and the content of fine powders,leads on a whole of interesting correlations.展开更多
The ongoing operation of subway systems makes existing tunnels vulnerable to deformations and structural damage caused by adjacent foundation pit construction.Such deformations-manifesting as horizontal displacement,h...The ongoing operation of subway systems makes existing tunnels vulnerable to deformations and structural damage caused by adjacent foundation pit construction.Such deformations-manifesting as horizontal displacement,heightened lateral convergence,and internal force redistribution-may significantly compromise subway operational safety.Grouting remediation has become a widely adopted solution for tunnel deformation control and structural reinforcement.Developing optimized grouting materials is crucial for improving remediation effectiveness,ensuring structural integrity,and maintaining uninterrupted subway operations.This investigation explores the substitution of fine mortar aggregates with 0.1 mm discarded rubber particles at varying concentrations(0%,3%,6%,9%,12%,and 15%).Experimental parameters included three water-cement ratios(0.65,0.70,and 0.75)with constant 4%WPU content.Mechanical properties including compressive strength,flexural strength,and compression-to-bending ratio were evaluated across specified curing periods.Material characterization employed Fourier Transform Infrared Spectroscopy(FTIR)spectroscopy for molecular analysis and Scanning Electron Microscopy(SEM)for microstructural examination.Results indicate optimal toughness at 0.70 water-cement ratio with 6%rubber content,meeting mechanical pumping specifications while maintaining structural performance.展开更多
Conventional natural rubber(NR)fillers pose several environmental concerns.This study presents the sustain-able development of NR composites incorporating sugarcane leaf(SCL)-derived alkali lignin and commercial alkal...Conventional natural rubber(NR)fillers pose several environmental concerns.This study presents the sustain-able development of NR composites incorporating sugarcane leaf(SCL)-derived alkali lignin and commercial alkali lignin as functional fillers.The primary objective was to evaluate the mechanical properties,aging resistance,thermal stability,and antimicrobial activity of the NR composites.Various NR composites were prepared by different filler types,including KOH-extracted SCL lignin,commercial alkali lignin,and butylated hydroxytoluene(BHT).The results show that NR composites containing KOH-extracted SCL lignin exhibited superior mechanical properties(crosslink density 126 mol/m^(3)),improved aging resistance(aging coefficient 80.08%),and enhanced thermal stability(the thermal degradation with 50%weight loss(T50)and the highest degradation rate occurs(Td)of 394 and 383℃,respectively)compared to all other samples.NR composites with commercial lignin demonstrated the highest reduction in Staphylococcus aureus populations(56.25%).The NR composites with KOH-extracted SCL lignin displayed limited antimicrobial efficacy(37.78%),suggesting that its primary contribution lies in mechanical and thermal reinforcement rather than microbial inhibition.These findings highlight the potential of eco-friendly lignin from SCL biomass as a sustainable bio-based filler for NR composites.展开更多
Fluorination is a critical surface modification technique for enhancing the electrical performance of composite insulators.This study employs molecular simulations to examine the microstructure and space charge behavi...Fluorination is a critical surface modification technique for enhancing the electrical performance of composite insulators.This study employs molecular simulations to examine the microstructure and space charge behavior of fluorinated and non-fluorinated silicone rubber under an electric field,with experimental validation.The results show that fluorinated silicone rubber exhibits lower total energy,higher polarization,and stronger dipole moments compared to its non-fluorinated counterpart,shifting the material from an insulating to a conductive state.Under lower electric field strengths,the carbon-silicon bonds in fluorinated silicone rubber are longer,but it maintains geometric stability under higher fields.The energy gap changes across different fluorination modes and varies with electric field strength,indicating that fluorination affects conductivity differently at various field intensities.Both fluorination methods improve conductivity in the 0–3.8 V/nm range,with substitutional fluorination showing superior performance between 3.8 and 8.9 V/nm.Above 9.1 V/nm,fluorination maximizes conductivity.The fluorinated samples exhibit a greater redshift at higher electric fields,resulting in enhanced conductivity and improved surface charge distribution.These findings offer insights into the microscopic effects of fluorination on silicone rubber’s electrical properties,while experiments confirm that fluorination increases hydrophobicity and boosts DC flashover voltage,further enhancing the material’s performance.展开更多
The thioacetamide derivative(TD)-composite preservation system(TDCPS)exhibits superior preservation effects on natural rubber latex(NRL)and significantly enhances its vulcanization efficiency and mechanical properties...The thioacetamide derivative(TD)-composite preservation system(TDCPS)exhibits superior preservation effects on natural rubber latex(NRL)and significantly enhances its vulcanization efficiency and mechanical properties.This study primarily investigated the principal chemical groups and mechanism of action of TDCPS in promoting NRL vulcanization through a comparative analysis.The results indicated that the key functional groups(thioamide and pyridine)in TDCPS synergistically accelerated crosslinking,reducing the vulcanization time by 41.18%compared to the high-ammonia(HA)preservation system.At an optimal TDCPS dosage of 5 mmol·L^(−1),vulcanized films achieved a tensile strength of 34.18 MPa,with a sulfur content of 1.5 phr further improving the strength by 42.26%.TD outperformed the conventional accelerators 2-imidazolidinethione(ETU)and 3-hydroxypyridine(3-Hp)in promoting the crosslinking density and mechanical performance while eliminating ammonia-related environmental risks.This eco-friendly system demonstrates the industrial potential for sustainable rubber production.展开更多
With the increasing and refined applications of silicone rubber devices in the biomedical field,it is of great significance to accurately describe and predict the mechanical behavior of them under large deformation.Th...With the increasing and refined applications of silicone rubber devices in the biomedical field,it is of great significance to accurately describe and predict the mechanical behavior of them under large deformation.This paper finds that after con-sidering the influence of higher-order shear strain on the normal stress,the Poynting effect in ribbed silicone rubber tubes with certain cross-sectional shapes exhibits a new phenomenon―a non-monotonic trend between axial deformation and twist angle.This paper develops a nonlinear finite element program for simulating large deformations of hyperelastic materials,and studies the Poynting effect in ribbed circular tubes of twisted silicone rubber.The results show that in the ribbed circular tubes with a porosity between 12% and 40%(with the number of ribs ranging from 12 to 26),there appears a normal to reverse conversion of the Poynting effect,that is,the axial extension ratio first decreases and then increases during a monotonic loading process,indicating that the influence of higher-order shear strain on normal stress cannot be ignored when the cross-sectional shape is complex.Especially in ribbed circular tubes with about 20% porosity,a substantial change of axial normal strain from−0.035% to 0.035% can be achieved within a twist angle range of 180°.Based on this,the quantitative influence of higher-order shear strain on normal stress is studied.These research results provide a theoretical basis for accurately controlling the axial expansion and contraction of twisted parts and indicate that a normal to reverse conversion of the Poynting effect can be implemented by designing the cross-sectional shape under certain conditions.展开更多
Rubberized concrete is one of the most studied applications of discarded tires and offers a promising approach to developing materials with enhanced properties.The rubberized concrete mixture results in a reduced modu...Rubberized concrete is one of the most studied applications of discarded tires and offers a promising approach to developing materials with enhanced properties.The rubberized concrete mixture results in a reduced modulus of elasticity and a reduced compressive and tensile strength compared to traditional concrete.This study employs finite element simulations to investigate the elastic properties of rubberized mortar(RuM),considering the influence of inclusion stiffness and interfacial debonding.Different homogenization schemes,including Voigt,Reuss,and mean-field approaches,are implemented using DIGIMAT and ANSYS.Furthermore,the influence of the interfacial transition zone(ITZ)between mortar and rubber is analyzed by periodic homogenization.Subsequently,the influence of the ITZ is examined through a linear fracture analysis with the stress intensity factor as a key parameter,using the ANSYS SMART crack growth tool.Finally,a non-linear study in FEniCS is carried out to predict the strength of the composite material through a compression test.Comparisons with high density polyethylene(HDPE)and gravel inclusions show that increasing inclusion stiffness enhances compressive strength far more effectively than simply improving the mortar/rubber bond.Indeed,when the inclusions are much softer than the surrounding matrix,any benefit gained on the elastic modulus or strength from stronger interfacial adhesion becomes almost negligible.This study provide numerical evidence that tailoring the rubber’s intrinsic stiffness—not merely strengthening the rubber/mortar interface—is a decisive factor for improving the mechanical performance of RuM.展开更多
基金supported by the Transportation Science and Technology Program of Henan Province(grant number:2023-4-2)the Key Research and Development Program of Ningxia Science and Technology Department(grant number:2022BEG02008)+2 种基金China Communications Construction Group Co.,Ltd.Science and Technology R&D Project(grant number:2021KJW02)the Research and Development Program of Henan Transportation Investment Group Co.,Ltd.(grant number:HNJT2025-1-9)the Postdoctoral Fellowship Program of CPSF(grand number:GZC20251139).
文摘The addition of high-content crumb rubber(HCCR)in asphalt can effectively address waste tire pollution and provide sustainable environmental and economic advantages.However,the practical application of conventional rubberized binders is significantly limited by high viscosity and poor storage stability.To address these issues,researchers have pretreated crumb rubber(CR)with oil,but high-temperature performance remains insufficient.Therefore,this study aimed to optimize the viscosity,storage stability,and rheological properties of high-content crumb rubber-modified asphalt(HCCRMA)by varying the pretreatment levels of CR and incorporating various additives,including styrene-butadiene-styrene(SBS),deoiled asphalt(DA),or recycled low-density polyethylene(RLDPE).In addition,CR was pretreated with waste cooking oil(WCO)at various ratios,pre-swelling temperatures,and times.The results show that DA exhibits excellent storage stability and lower viscosity compared with other modifiers in HCCRMA,and the 4%RLDPE with pretreated HCCR has the greatest high-temperature rutting resistance.The inclusion of RLDPE increases the stiffness and elasticity of the modified asphalt,which results in greater high-temperature performance.Additionally,the fluorescence microscopy(FM)test confirms that SBS exhibits better dispersion than other modifiers and forms a more homogeneous phase separation in the HCCRMA.All in all,this research achieved an optimal balance of storage stability and rheological properties in asphalt modified with pretreated HCCR and 6%SBS,which provides a valuable reference for performance improvement of HCCR-modified binders.
基金financially supported by the National Natural Science Foundation of China(No.52363007)。
文摘Recycling of waste rubber(WR)is crucial for the sustainable development of the rubber industry.The enhancement of interfacial interactions is the main strategy for waste polymer recycling.However,there is a lack of methods for enhancing the interfacial interactions for WR recycling because WR contains abundant inert C―H bonds.Herein,we designed thioctic acid inverse vulcanization copolymers to endow recycled WR with dynamic disulfide interfacial interactions,significantly improving the mechanical properties of recycled WR.These disulfide interfacial interactions among the recycled WR tend to exchange,which dramatically increases the fractocohesive length and prevents stress concentration near the crack tips.When recycled WR is subjected to external stress,the loads are redistributed across a broad region of adjacent regions instead of being concentrated on a limited length scale,which resists crack propagation.This work effectively recycled WR,providing a strategy for solvent-free reaction-derived inverse vulcanization copolymers to improve the toughness of WR recycling.
基金supported by the RIIM BRIN and LPDP Grants,grant number B-2880/II.7.5/KS.00/4/2025 dan B-7930/III.6/TK.01.03/4/2025 under the scheme BRIN-KONEKSI Joint Call for Proposalsthe theme“Indonesia's Bioeconomy:Maximising Sustainable Marine Biodiversity Utilisation 2024”No 6/II.7/HK/2025.
文摘This study investigates the potential of starch extracted from underutilized agro-industrial resources as non-food-competing raw materials for the development of flexible bioplastics for food packaging applications.Starch was extracted from three biomass sources:rubber cassava(Manihot glaziovii),banana stem,and banana peel from Ambonese banana(Musa acuminata L.).Rubber cassava starch(SRC)exhibited the highest starch yield(50.68±0.28%),significantly surpassing banana stem(SBS,14.20±0.25%)and banana peel(SBP,3.07±0.15%).The amylose contents of SRC,SBS,and SBP were 28.18%,52.80%,and 56.57%,respectively,while their amylopectin contents were 71.83%,47.20%,and 43.43%.FTIR spectra confirmed the absence of cyanogenic groups in SRC,indicating its safety for packaging applications.XRD analysis revealed that PSRC films were predominantly amorphous,while PSBS and PSBP showed higher crystallinity.The enhancement of mechanical properties,specifically PSBS,showed the highest tensile strength at 16.04±0.56 MPa,whereas PSRC demonstrated the highest elongation at break at 23.57±0.40%,which could be attributed to the inherent characteristics of the starch sources.Additionally,PSRC film exhibited the highest transparency at 60.2%,the greatest water solubility at 34.92%,and the lowest water contact angle at 41.58○,confirming its more hydrophilic nature compared to other films.This work highlights the potential of low-cost,sustainable,and non-food agro-industrial starch sources as promising candidates for the development of flexible,eco-friendly bioplastics.
基金supported by the National Natural Science Foundation of China(grant numbers 52250357 and 52203003).
文摘The glass transition temperature(T_(g))of styrene-butadiene rubber(SBR)is a key parameter determining its low-temperature flexibility and processing performance.Accurate prediction of T_(g)is crucial formaterial design and application optimisation.Addressing the limitations of traditional experimental measurements and theoretical models in terms of efficiency,cost,and accuracy,this study proposes a machine learning prediction framework that integrates multi-model ensemble and Bayesian optimization by constructing a multi-component feature dataset and algorithm optimization strategy.Based on the constructed high-quality dataset containing 96 SBR samples,ninemachine learning models were employed to predict the T_(g)of SBR and compare their prediction performance.Ultimately,aGPR-XGBoost mixed model was constructed through model ensemble,achieving high-precision prediction with R^(2)values greater than 0.9 on both the training and test sets.Further feature attribution and local effect analysis were conducted using feature analysis methods such as SHAP and ALE,revealing the nonlinear influence patterns of various components on T_(g),providing a theoretical basis for SBR formulation design and T_(g)regulation.The machine learning prediction framework established in this study combines high-precision prediction with interpretability,significantly enhancing the prediction performance of the T_(g)of SBR.It offers an efficient tool for SBR molecular design and holds great potential for promotion and application.
基金supported by the National Natural Science Foundation of China(No.52293471)National Key R&D Program of China(No.2022YFB3707303).
文摘The flocculation behavior of carbon black (CB)-filled isoprene rubber (IR) nanocomposites was systematically investigated under both dynamic and static conditions to unravel the distinct mechanisms governing filler network evolution.Under dynamic conditions,small oscillatory shear strains (0.1%) significantly enhanced filler particle motion,leading to pronounced agglomeration and a flocculation degree of about 4.3MPa at 145℃.In contrast,static flocculation exhibited a fundamentally different mechanism dominated by polymer chain dynamics,which is driven mainly by thermal activation.Radial distribution function (RDF) analysis of transmission electron microscopy (TEM) images revealed a slight decrease (2 nm) in the interparticle distance peak after static annealing at 100℃ for 7 h,indicating localized motion of CB particles.However,the overall filler network remained stable,with no significant agglomeration observed.The increase in bound rubber content from about 23% to 28% with rising temperature further confirmed the dominant role of polymer chain adsorption and interfacial reinforcement in static flocculation.These findings highlight the critical influence of external strain on filler network formation and provide new insights into the polymer-dominated mechanism of static flocculation.The results offer practical guidance for optimizing the storage and processing of rubber nanocomposites,particularly in applications where static flocculation during prolonged storage is a concern.
基金funded by Tianjin Key Medical Discipline(Specialty)Construction Project(TJYXZDXK-007A).
文摘Immunosuppressed patients have increased susceptibility to various infections,including opportunistic infections.The risk of infective complications in these patients is significantly higher,which can lead to more severe infections,prolonged illness course,and an increased likelihood of poor outcome,including sepsis,organ failure,and even death.Blue rubber bleb nevus syndrome(BRBNS)is a rare syndrome characterized by venous malformations primarily found in the skin and gastrointestinal(GI)tract.
基金supported by the Natural Science Foundation of Sichuan Province(No.2024NSFSC0173)the National Natural Science Foundation of China(Nos.5240030820,52173058 and 52403072)National Key R&D Program of China(No.2022YFD2301202)。
文摘Natural rubber(NR)is a crucial elastic material used for damping and sealing applications in the nuclear industry,but its mechanical stability under radiation remains inadequate.Current efforts to improve radiation resistance rely on the addition of antiradiation agents,however,the effects of the components and microstructures of NR itself on radiation resistance remain unclear.In this study,we compared the composition and structure differences of four typical commercially used NR materials and investigated their effects on gamma radiation resistance.Furthermore,we examined the impact of non-rubber components(NRC)in NR on radiation resistance using deproteinized and dephosphorylated NR model samples.Our results revealed that NRC,such as proteins and phospholipids can enhance the strength of natural rubber before radiation exposure.However,after the removal of NRC,the samples exhibited improved mechanical stability under irradiation.Additionally,the ash content in NR could also influence the radiation resistance,as metal ions may react with the active centers produced by radiation,thereby enhancing the radiation resistance of the rubber.This work identifies the effect of non-rubber components in NR on radiation resistance and may serve as a reference for screening and developing radiation-resistant NR materials.
基金funded by Faculty of Engineering,Burapha University,grant number 003/2567.
文摘Herein,cure characteristics,morphology,and mechanical properties of natural rubber filled with activated carbon-based materials were investigated.Carbon-based materials were prepared from bagasse,coffee grounds and pineapple crowns by the pyrolysis method at temperatures in the range of 300℃.As-synthesized carbon materials were characterized by optical microscopy(OM),scanning electron microscopy(SEM),and Fourier-transform infrared spectroscopy(FTIR)to analyze size distribution,morphology,and functional groups,respectively.OM and SEM analysis revealed that particles,flakes,and a small quantity of fiber-like carbon were obtained using bagasse and pineapple crown as raw materials,while honeycomb-like carbon materials can be derived from coffee grounds.To investigate the mechanical properties,natural rubber was filled with carbon black and as-synthesized carbon materials by the internal mixing and compression molding process.Transmission electron microscopy(TEM)was utilized to characterize the dispersion of carbon materials in the rubber matrix.The results of tensile testing showed that the natural rubber mixed with as-synthesized carbon materials from pineapple crowns exhibited 54%and 74%improvement in the ultimate tensile strength and Young’s modulus,respectively,compared with natural rubber without filled carbon materials.The enhancement in mechanical properties by activated carbon materials derived from pineapple crowns can be attributed to the flake-and fiber-like structures and good dispersion of carbon materials in the rubber matrix.In addition,it is higher than that of rubber mixed with carbon black.The results demonstrated that as-synthesized carbon materials from pineapple crowns have the potential materials to substitute carbon black in the rubber compound industry.
基金supported by the Science and Technology Research and Development Plan of the China State Railway Group Company Limited(No.Q2023J012).
文摘Purpose–The brake pipe system was an essential braking component of the railway freight trains,but the existing E-type sealing rings had problems such as insufficient low-temperature resistance,poor heat stability and short service life.To address these issues,low-phenyl silicone rubber was prepared and tested,and the finite element analysis and experimental studies on the sealing performance of its sealing rings were carried out.Design/methodology/approach–The low-temperature resistance and thermal stability of the prepared lowphenyl silicone rubber were studied using low-temperature tensile testing,differential scanning calorimetry,dynamic thermomechanical analysis and thermogravimetric analysis.The sealing performance of the lowphenyl silicone rubber sealing ring was studied by using finite element analysis software abaqus and experiments.Findings–The prepared low-phenyl silicone rubber sealing ring possessed excellent low-temperature resistance and thermal stability.According to the finite element analysis results,the finish of the flange sealing surface and groove outer edge should be ensured,and extrusion damage should be avoided.The sealing rings were more susceptible to damage in high compression ratio and/or low-temperature environments.When the sealing effect was ensured,a small compression ratio should be selected,and rubbers with hardness and elasticity less affected by temperature should be selected.The prepared low-phenyl silicone rubber sealing ring had zero leakage at both room temperature(RT)and�508C.Originality/value–The innovation of this study is that it provides valuable data and experience for the future development of the sealing rings used in the brake pipe flange joints of the railway freight cars in China.
基金funded under the Collaborative Research Initiative Grant Scheme(C-RIGS),grant number C-RIGS24-016-0022 from IIUM.
文摘This review provides a comprehensive overview of natural rubber(NR)composites,focusing on their properties,compounding aspects,and renewable practices involving natural fibre reinforcement.The properties of NR are influenced by the compounding process,which incorporates ingredients such as elastomers,vulcanizing agents,accelerators,activators,and fillers like carbon black and silica.While effective in enhancing properties,these fillers lack biodegradability,prompting the exploration of sustainable alternatives.The potential of natural fibres as renewable reinforcements in NR composites is thoroughly covered in this review,highlighting both their advan-tages,such as improved sustainability,and the challenges they present,such as compatibility with the rubber matrix.Surface treatment methods,including alkali and silane treatments,are also discussed as solutions to improve fibre-matrix adhesion and mitigate these challenges.Additionally,the review highlights the potential of oil palm empty fruit bunch(EFB)fibres as a natural fibre reinforcement.The abundance of EFB fibres and their alignment with sustainable practices make them promising substitutes for conventional fillers,contributing to valuable knowledge and supporting the broader move towards renewable reinforcement to improve sustain-ability without compromising the key properties of rubber composites.
基金supported by National Natural Science Foundation of China(51991352 and 51874266).
文摘Silicone rubber(SR)exhibits superior breathability and high-temperature resistance.However,SR is prone to degradation under extreme heat or combustion,limiting its effectiveness in mitigating secondary hazards.In this study,phosphate glass powder was used to calcinate zinc borate,lanthanum oxide,and cerium oxide.Methylphenyl polysiloxane was then grafted onto the surface of the glass powder,resulting in the modified pow-ders designated as Methylphenyl polysiloxane-grafted zinc borate-modified phosphate glass powder(GF-ZnBM),Methylphenyl polysiloxane-grafted lanthanum oxide-modified phosphate glass powder(GF-LaM),and Methylphenyl polysiloxane-grafted cerium oxide-modified phosphate glass powder(GF-CeM).The modified powders were sub-sequently incorporated into silicone rubber composites to enhance the ceramicization capability of silicone rubber at high temperatures.Specifically,GF-CeM and GF-LaM significantly increased the limiting oxygen index(LOI)to 33%and reduced the tendency for combustion propagation.Additionally,GF-CeM notably contributed to enhancing ceramicization strength.The presence of cerium oxide helps in the melting of the glass powder and enhances its adhesion to the silicone rubber matrix.SR/ZnB-GF exhibited the lowest activation energy among the tested composites,along with the best protective capability.The inclusion of modified glass powder has a minor impact on the rheological properties,indicating that the composite retains its ability to flow and deform under stress.This confirms that the material remains flexible under normal conditions and forms a ceramic structure when heated,thereby exhibiting self-supporting properties.This study provides a practical methodology for the targeted modification of glass powders,thereby further enhancing the fire safety of silicone-based composites.
基金supported by the Strategic Priority Program of the Chinese Academy of Sciences(XDB0470303)the National Key R&D Program of China(2022YFB4600102and 2023YFE0209900)+4 种基金the National Natural Science Foundation of China(52175201 and 51935012)the science and technology projects of Gansu province(22JR5RA093,24JRRA044,24YFFA014 and 24ZDGA014)the Innovation and Entrepreneurship Team Project of YEDA(2021TD007)the special supporting project for provincial leading talents of Yantaithe Taishan Scholars Program。
文摘Silicone rubber(SR)is a versatile material widely used across various advanced functional applications,such as soft actuators and robots,flexible electronics,and medical devices.However,most SR molding methods rely on traditional thermal processing or direct ink writing three-dimensional(3D)printing.These methods are not conducive to manufacturing complex structures and present challenges such as time inefficiency,poor accuracy,and the necessity of multiple steps,significantly limiting SR applications.In this study,we developed an SR-based ink suitable for vat photopolymerization 3D printing using a multi-thiol monomer.This ink enables the one-step fabrication of complex architectures with high printing resolution at the micrometer scale,providing excellent mechanical strength and superior chemical stability.Specifically,the optimized 3D printing SR-20 exhibits a tensile stress of 1.96 MPa,an elongation at break of 487.9%,and an elastic modulus of 225.4 kPa.Additionally,the 3D-printed SR samples can withstand various solvents(acetone,toluene,and tetrahydrofuran)and endure temperatures ranging from-50℃ to 180℃,demonstrating superior stability.As a emonstration of the application,we successfully fabricated a series of SR-based soft pneumatic actuators and grippers in a single step with this technology,allowing for free assembly for the first time.This ultraviolet-curable SR,with high printing resolution and exceptional stability performance,has significant potential to enhance the capabilities of 3D printing for applications in soft actuators,robotics,flexible electronics,and medical devices.
基金National Natural Science Foundation of China(12262028)Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(NJYT22085)Inner Mongolia Autonomous Region Science and Technology Plan Project(2021GG0437)。
文摘The predictive model and design of heavy-duty metal rubber shock absorber for the powertrains of heavy-load mining vehicles were investigated.The microstructural characteristics of the wire mesh were elucidated using fractal graphs.A numerical model based on virtual fabrication technique was established to propose a design scheme for the wire mesh component.Four sets of wire mesh shock absorbers with various relative densities were prepared and a predictive model based on these relative densities was established through mechanical testing.To further enhance the predictive accuracy,a variable transposition fitting method was proposed to refine the model.Residual analysis was employed to quantitatively validate the results against those obtained from an experimental control group.The results show that the improved model exhibits higher predictive accuracy than the original model,with the determination coefficient(R^(2))of 0.9624.This study provides theoretical support for designing wire mesh shock absorbers with reduced testing requirements and enhanced design efficiency.
文摘Rubbery waste at the end of the cycle often constitutes a threat for the environment because of their encumbrance and low biodeterioration.The purpose of the research presented is to develop the rubber fine powder as a pavement.It is interested primarily in the behavior of two types of bitumen 40/50 modified by the addition of two varieties of rubber fine powders of different grading,resulting from the crushing of the rubbery products intended for the clothes industry of soles of shoes.The objective of the experimentation is to study the influence of the added polymer on the physical properties of the ordinary road bitumen with the incorporation of the fine powder.The experimental approach is carried out using the two tests of characterization of the bitumen i.e.the softening point test and the penetration test which remain the most used to define and classify the road bitumen.It will be noted however,that the experimental investigation which is based on several tests according to the type and the content of fine powders,leads on a whole of interesting correlations.
基金supported by the National Natural Science Foundation of China,Grant Nos.42477185,41602308the Zhejiang Provincial Natural Science Foundation of China,Grant No.LY20E080005+2 种基金the Zhejiang Province University Students Science and Technology Innovation Program,Grant No.0201310P28the PostGraduate Course Construction Project of Zhejiang University of Science and Technology,Grant No.2021yjskj05the Zhejiang University of Science and Technology Graduate Research and Innovation Fund,Grant No.2023yjskc10.
文摘The ongoing operation of subway systems makes existing tunnels vulnerable to deformations and structural damage caused by adjacent foundation pit construction.Such deformations-manifesting as horizontal displacement,heightened lateral convergence,and internal force redistribution-may significantly compromise subway operational safety.Grouting remediation has become a widely adopted solution for tunnel deformation control and structural reinforcement.Developing optimized grouting materials is crucial for improving remediation effectiveness,ensuring structural integrity,and maintaining uninterrupted subway operations.This investigation explores the substitution of fine mortar aggregates with 0.1 mm discarded rubber particles at varying concentrations(0%,3%,6%,9%,12%,and 15%).Experimental parameters included three water-cement ratios(0.65,0.70,and 0.75)with constant 4%WPU content.Mechanical properties including compressive strength,flexural strength,and compression-to-bending ratio were evaluated across specified curing periods.Material characterization employed Fourier Transform Infrared Spectroscopy(FTIR)spectroscopy for molecular analysis and Scanning Electron Microscopy(SEM)for microstructural examination.Results indicate optimal toughness at 0.70 water-cement ratio with 6%rubber content,meeting mechanical pumping specifications while maintaining structural performance.
基金This research project(Grant No FF-112/2566)is supported by Mahidol University(Basic Research Fund:fiscal year 2023 by National Science Research and Innovation Fund(NSRF)).
文摘Conventional natural rubber(NR)fillers pose several environmental concerns.This study presents the sustain-able development of NR composites incorporating sugarcane leaf(SCL)-derived alkali lignin and commercial alkali lignin as functional fillers.The primary objective was to evaluate the mechanical properties,aging resistance,thermal stability,and antimicrobial activity of the NR composites.Various NR composites were prepared by different filler types,including KOH-extracted SCL lignin,commercial alkali lignin,and butylated hydroxytoluene(BHT).The results show that NR composites containing KOH-extracted SCL lignin exhibited superior mechanical properties(crosslink density 126 mol/m^(3)),improved aging resistance(aging coefficient 80.08%),and enhanced thermal stability(the thermal degradation with 50%weight loss(T50)and the highest degradation rate occurs(Td)of 394 and 383℃,respectively)compared to all other samples.NR composites with commercial lignin demonstrated the highest reduction in Staphylococcus aureus populations(56.25%).The NR composites with KOH-extracted SCL lignin displayed limited antimicrobial efficacy(37.78%),suggesting that its primary contribution lies in mechanical and thermal reinforcement rather than microbial inhibition.These findings highlight the potential of eco-friendly lignin from SCL biomass as a sustainable bio-based filler for NR composites.
基金supported in part by the National Natural Science Foundation of China under Grant 52277139 and 52367014in part by the Guangxi Science Fund for Distinguished Young Scholars under Grant 2024GXNSFFA999017.
文摘Fluorination is a critical surface modification technique for enhancing the electrical performance of composite insulators.This study employs molecular simulations to examine the microstructure and space charge behavior of fluorinated and non-fluorinated silicone rubber under an electric field,with experimental validation.The results show that fluorinated silicone rubber exhibits lower total energy,higher polarization,and stronger dipole moments compared to its non-fluorinated counterpart,shifting the material from an insulating to a conductive state.Under lower electric field strengths,the carbon-silicon bonds in fluorinated silicone rubber are longer,but it maintains geometric stability under higher fields.The energy gap changes across different fluorination modes and varies with electric field strength,indicating that fluorination affects conductivity differently at various field intensities.Both fluorination methods improve conductivity in the 0–3.8 V/nm range,with substitutional fluorination showing superior performance between 3.8 and 8.9 V/nm.Above 9.1 V/nm,fluorination maximizes conductivity.The fluorinated samples exhibit a greater redshift at higher electric fields,resulting in enhanced conductivity and improved surface charge distribution.These findings offer insights into the microscopic effects of fluorination on silicone rubber’s electrical properties,while experiments confirm that fluorination increases hydrophobicity and boosts DC flashover voltage,further enhancing the material’s performance.
基金the Ministry of Agriculture and Rural Affairs of Chinathe Department of Science and Technology of the Hainan Province for their support+2 种基金financially supported by the National Key R&D Program of China(No. 2022YFD2301201)Hainan Province Science and Technology Special Fund (No. ZDYF2024XDNY284)Earmarked Fund for China Agriculture Research System (No.CARS-33-JG1)
文摘The thioacetamide derivative(TD)-composite preservation system(TDCPS)exhibits superior preservation effects on natural rubber latex(NRL)and significantly enhances its vulcanization efficiency and mechanical properties.This study primarily investigated the principal chemical groups and mechanism of action of TDCPS in promoting NRL vulcanization through a comparative analysis.The results indicated that the key functional groups(thioamide and pyridine)in TDCPS synergistically accelerated crosslinking,reducing the vulcanization time by 41.18%compared to the high-ammonia(HA)preservation system.At an optimal TDCPS dosage of 5 mmol·L^(−1),vulcanized films achieved a tensile strength of 34.18 MPa,with a sulfur content of 1.5 phr further improving the strength by 42.26%.TD outperformed the conventional accelerators 2-imidazolidinethione(ETU)and 3-hydroxypyridine(3-Hp)in promoting the crosslinking density and mechanical performance while eliminating ammonia-related environmental risks.This eco-friendly system demonstrates the industrial potential for sustainable rubber production.
基金supported by the National Natural Science Foundation of China(Grant Nos.52009107 and 11972285)the Youth Innovation Team Project of Shaanxi Provincial Department of Education(Grant No.21JP079).
文摘With the increasing and refined applications of silicone rubber devices in the biomedical field,it is of great significance to accurately describe and predict the mechanical behavior of them under large deformation.This paper finds that after con-sidering the influence of higher-order shear strain on the normal stress,the Poynting effect in ribbed silicone rubber tubes with certain cross-sectional shapes exhibits a new phenomenon―a non-monotonic trend between axial deformation and twist angle.This paper develops a nonlinear finite element program for simulating large deformations of hyperelastic materials,and studies the Poynting effect in ribbed circular tubes of twisted silicone rubber.The results show that in the ribbed circular tubes with a porosity between 12% and 40%(with the number of ribs ranging from 12 to 26),there appears a normal to reverse conversion of the Poynting effect,that is,the axial extension ratio first decreases and then increases during a monotonic loading process,indicating that the influence of higher-order shear strain on normal stress cannot be ignored when the cross-sectional shape is complex.Especially in ribbed circular tubes with about 20% porosity,a substantial change of axial normal strain from−0.035% to 0.035% can be achieved within a twist angle range of 180°.Based on this,the quantitative influence of higher-order shear strain on normal stress is studied.These research results provide a theoretical basis for accurately controlling the axial expansion and contraction of twisted parts and indicate that a normal to reverse conversion of the Poynting effect can be implemented by designing the cross-sectional shape under certain conditions.
基金financial support from the Chilean National Agency for Research and Development(ANID),National Doctorate No.21212028financial support from ANID,FONDECYT Regular Research Project No.1221793.
文摘Rubberized concrete is one of the most studied applications of discarded tires and offers a promising approach to developing materials with enhanced properties.The rubberized concrete mixture results in a reduced modulus of elasticity and a reduced compressive and tensile strength compared to traditional concrete.This study employs finite element simulations to investigate the elastic properties of rubberized mortar(RuM),considering the influence of inclusion stiffness and interfacial debonding.Different homogenization schemes,including Voigt,Reuss,and mean-field approaches,are implemented using DIGIMAT and ANSYS.Furthermore,the influence of the interfacial transition zone(ITZ)between mortar and rubber is analyzed by periodic homogenization.Subsequently,the influence of the ITZ is examined through a linear fracture analysis with the stress intensity factor as a key parameter,using the ANSYS SMART crack growth tool.Finally,a non-linear study in FEniCS is carried out to predict the strength of the composite material through a compression test.Comparisons with high density polyethylene(HDPE)and gravel inclusions show that increasing inclusion stiffness enhances compressive strength far more effectively than simply improving the mortar/rubber bond.Indeed,when the inclusions are much softer than the surrounding matrix,any benefit gained on the elastic modulus or strength from stronger interfacial adhesion becomes almost negligible.This study provide numerical evidence that tailoring the rubber’s intrinsic stiffness—not merely strengthening the rubber/mortar interface—is a decisive factor for improving the mechanical performance of RuM.
