Chinese bamboo flour was chemically modified by acetylation with acetic anhydride by using trichloroacetic acid as an activation agent and the optimized condition for acetylation of bamboo flour was determined as the ...Chinese bamboo flour was chemically modified by acetylation with acetic anhydride by using trichloroacetic acid as an activation agent and the optimized condition for acetylation of bamboo flour was determined as the trichloroacetic acid amount 6.0 g per 1.5-g bamboo flour, ultrasosonication duration 40 min and the reaction time 1 h at 65℃. The composition, microstructure and thermal behavior of acetylated bamboo flour were preliminarily characterized by FT-IR, DSC and SEM etc. The acetylated bamboo flour can be molded into sheets at 130℃ and 10 MPa, indicating the modified bamboo flour possesses thermalplastic performance.展开更多
After the heavy reduction(HR)process was carried out at the solidification end of the continuous casting slab,the austenite grains were refined by recrystallization,which improved the thermoplasticity of the slab.Howe...After the heavy reduction(HR)process was carried out at the solidification end of the continuous casting slab,the austenite grains were refined by recrystallization,which improved the thermoplasticity of the slab.However,the reduction in deformation during the HR process initiated stress concentration at the slab surface,and the crack risk increased.To effectively evaluate the risk of slab surface cracks under these complex conditions,the effect of the HR on the austenite recrystallization and thermoplasticity of a microalloyed slab surface was investigated by 15-pass reduction thermal simulation according to the wide and thick slab continuous casting process.The softening fraction was introduced as a global internal variable to quantitatively analyze various recrystallized re-refined grains.After the critical strain reaches the critical strain of dynamic recrystallization,a variety of recrystallization modes alternately occur.Among them,the contribution rate of dynamic crystallization to the later refinement reaches more than 50%.The contribution rates of static recrystallization and metadynamic recrystallization to grain refinement are almost the same.The thermoplasticity of the slab surface first increases and then decreases with increasing reduction pass.It was verified by transmission electron microscopy that the main reason for the decrease in thermoplasticity is that the dislocation multiplication rate increases,resulting in a sharp increase in stress and a decrease in thermoplasticity.展开更多
Through the addition of appropriate amount of Mg （0.01-0.01 5 wt%） to the stainless bearing steel Cr14Mo4, the high-temperature thermoplasticity of steel was improved. The mechanism has been uncovered that the added...Through the addition of appropriate amount of Mg （0.01-0.01 5 wt%） to the stainless bearing steel Cr14Mo4, the high-temperature thermoplasticity of steel was improved. The mechanism has been uncovered that the added Mg plays an important role in refining and uniforming the carbide precipitations in the steel. It has been found that the segregation of trace Mg is the key to improve the dispersed carbide. Moreover, considerable segregation of Mg in steel during annealing was evidenced by the theoretic analysis.展开更多
Concrete production often relies on natural aggregates,which can lead to resource depletion and environmental harm.In addition,improper disposal of thermoplastic waste exacerbates ecological problems.Although signific...Concrete production often relies on natural aggregates,which can lead to resource depletion and environmental harm.In addition,improper disposal of thermoplastic waste exacerbates ecological problems.Although significant attention has recently been given to recycling various waste materials into concrete,studies specifically addressing thermoplastic recycled aggregates are still trending.This underscores the need to comprehensively review existing literature,identify research trends,and recognize gaps in understanding the mechanical performance of thermoplastic-based recycled aggregate concrete.Accordingly,this review summarizes recent investigations focused on the mechanical properties of thermoplastic-based recycled aggregate concrete,emphasizing aspects such as compressive strength,tensile behavior,modulus of elasticity,and durability characteristics.The primary aim is to consolidate scattered research findings,identify key parameters influencing mechanical behavior,and propose future research directions.Understanding the influence of recycled thermoplastic aggregates on concrete performance significantly supports sustainable construction practices by reducing dependency on virgin aggregates and mitigating environmental impacts associated with waste disposal.In addition,assessing mechanical performance contributes to confidence in the practical application,encouraging the broader adoption of thermoplastic-based recycled aggregate concrete in construction projects.Through this critical synthesis,the review guides researchers and industry practitioners toward informed decisions on the feasibility and reliability of integrating thermoplastic waste into concrete,thereby promoting sustainable infrastructure development.展开更多
Thermoplastic polyurethane(TPU)consists of a hardsegment and a soft segment,where the former affords mechanical strength and thermalstability,while the latter provides a possibility of good ionic conductivity by promo...Thermoplastic polyurethane(TPU)consists of a hardsegment and a soft segment,where the former affords mechanical strength and thermalstability,while the latter provides a possibility of good ionic conductivity by promoting dissociation of ions from the lithium salt.Thus,TPU attracts a wide interest recently as a promising polymer electrolyte for solid-state lithium batteries.However,the relatively low ionic conductivity of TPU still restricts its actual applications due to the aggregation of polymer chains,which greatly reduces the dissociation of lithium salts.Herein,a strategy to address this challenge was adopted by in situ polymerization poly(ethylene glycol diacrylate)(PEGDA)in fully dispersed TPU.Hence a stretchable solid-state electrolyte(denoted as TELL and the contrast sample was denoted as TLL)with high ionic conductivity of 7.18×10^(-4) S/cm was obtained at room temperature.The Li^(+)transference number is 0.85 in Li|TELL|Li cell and can stably undergo charge-discharge cycles for 1400 h at a current density of O.1 mA/cm^(2),while the contrast sample is short-circuited after 634 h of cycling.The LiFePO_(4)|TELL|Li cell achieves a capacity retention of 78.93%after 200 cycles at 2 C.The LiFePO_(4) TLL Li cellonly gains the capacity retention of 51.9%after 50 cyclesat the same current density.So,the method adopted here may provide a new approach to realize a flexible solid-state electrolyte with high ion-conductivity.展开更多
This study represents an important step forward in the domain of additive manufacturing of energetic materials.It presents the successful formulation and fabrication by 3D printing of gun propellants using Fused Depos...This study represents an important step forward in the domain of additive manufacturing of energetic materials.It presents the successful formulation and fabrication by 3D printing of gun propellants using Fused Deposition Modeling(FDM)technology,highlighting the immense potential of this innovative approach.The use of FDM additive manufacturing technology to print gun propellants is a significant advancement due to its novel application in this field,which has not been previously reported.Through this study,the potential of FDM 3D-printing in the production of high-performance energetic composites is demonstrated,and also a new standard for manufacturability in this field can be established.The thermoplastic composites developed in this study are characterized by a notably high energetic solids content,comprising 70%hexogen(RDX)and 10%nitrocellulose(NC),which surpasses the conventional limit of 60%energetic solids typically achieved in stereolithography and light-curing 3D printing methods.The primary objective of the study was to optimize the formulation,enhance performance,and establish an equilibrium between printability and propellant efficacy.Among the three energetic for-mulations developed for 3D printing feedstock,only two were suitable for printing via the FDM tech-nique.Notably,the formulation consisting of 70%RDX,10%NC,and 20%polycaprolactone(PCL)emerged as the most advantageous option for gun propellants,owing to its exceptional processability,ease of printability,and high energetic performance.展开更多
Liquid leakage of pipeline networks not only results in considerableresource wastage but also leads to environmental pollution and ecological imbalance.In response to this global issue, a bioinspired superhydrophobic ...Liquid leakage of pipeline networks not only results in considerableresource wastage but also leads to environmental pollution and ecological imbalance.In response to this global issue, a bioinspired superhydrophobic thermoplastic polyurethane/carbon nanotubes/graphene nanosheets flexible strain sensor (TCGS) hasbeen developed using a combination of micro-extrusion compression molding andsurface modification for real-time wireless detection of liquid leakage. The TCGSutilizes the synergistic effects of Archimedean spiral crack arrays and micropores,which are inspired by the remarkable sensory capabilities of scorpions. This designachieves a sensitivity of 218.13 at a strain of 2%, which is an increase of 4300%. Additionally, it demonstrates exceptional durability bywithstanding over 5000 usage cycles. The robust superhydrophobicity of the TCGS significantly enhances sensitivity and stability indetecting small-scale liquid leakage, enabling precise monitoring of liquid leakage across a wide range of sizes, velocities, and compositionswhile issuing prompt alerts. This provides critical early warnings for both industrial pipelines and potential liquid leakage scenariosin everyday life. The development and utilization of bioinspired ultrasensitive flexible strain sensors offer an innovative and effectivesolution for the early wireless detection of liquid leakage.展开更多
Bio-based thermoplastic film from flax fiber and fatty acid(FA)was obtained using trifluoroacetic anhydride(TFAA)as an impelling agent.Different quantities of TFAA/FA,size of flax fiber,and fatty acids were applied to...Bio-based thermoplastic film from flax fiber and fatty acid(FA)was obtained using trifluoroacetic anhydride(TFAA)as an impelling agent.Different quantities of TFAA/FA,size of flax fiber,and fatty acids were applied to investigate chemical structure in relation to the mechanical properties.Decreasing the quantity of TFAA/FA by almost half from 1:4 to 1:2.5(flax to TFAA/FA)only reduces by 22%the weight percent gain(WPG)and ester content and reducing flax fiber size slightly increases the WPG and ester content.All the treatments showed sig-nificant chemical structure modification,observed by FTIR and solid CP/MAS^(13)C NMR,confirming the presence of carbonyl ester groups and alkyl chains,in relatively similar intensities.The crystallinity index(CrI)of esterified flax was evaluated by comparing the signal of solid CP/MAS^(13)C NMR in crystalline and amorphous regions and CrI was higher in esterified flax using a lower quantity of reagent and longer fatty acid.Esterified flax in a high quantity of reagent showed ductile or flexible behavior.Decreasing the reagent to 1:2.5 significantly increases the tensile strength and Young’s modulus,and decreases the elongation at break,presenting more brittle and stiff material.Using flax fiber in the original size results in slightly higher tensile strength and Young’s modulus and slightly lower elongation than milled flax.The tensile strength and Young’s modulus of stearic acid esterified flax obtained in this research were higher than myristic acid and comparable to the polyethylene plastics-LDPE and HDPE.展开更多
The use of wood-polymer composites(WPC)based on a polymer matrix and wood filler is a modern,environmentally friendly direction in material science.However,untreated wood filler exhibits poor adhesion to hydrophobic p...The use of wood-polymer composites(WPC)based on a polymer matrix and wood filler is a modern,environmentally friendly direction in material science.However,untreated wood filler exhibits poor adhesion to hydrophobic polymers due to its hydrophilic lignocellulose fibers.To address this,ozone treatment is employed to enhance compatibility,reduce water absorption,and regulate biodegradation rates.This study investigates the hypothesis that ozone modification of wood filler improves adhesion to thermoplastic starch,thereby enhancing the physico-mechanical properties and controlled biodegradation of WPCs under compost conditions.A compre-hensive analysis was conducted on composites containing untreated and ozonated wood flour,focusing on tensile strength,bending resistance,impact strength,and biodegradation kinetics.Results showed significant improvements in mechanical properties for modified composites:tensile strength increased by 20%-25%,bending resistance by 15%-30%,and impact strength by 15%-20% compared to untreated samples.The optimal composition identified contained 70% ozonated wood flour and 30% thermoplastic starch(70WF/30P),demonstrating excellent mechanical strength(flexural strength of 18-22MPa),complete biodegradation within 140 days,and operational stability.The study revealed correlations between surface modification,interphase interaction,and biodegradation kinetics,advancing fundamental knowledge of lignocellulosic filler modification methods.These findings are crucial for developing eco-friendly composite materials with applications in biodegradable packaging and agricultural products,offering both scientific insights and practical solutions for sustainable material development.展开更多
This paper presents the development of a thermoplastic shape memory rubber that can be programmed at human body temperature for comfortable fitting applications.We hybridized commercially available thermoplastic rubbe...This paper presents the development of a thermoplastic shape memory rubber that can be programmed at human body temperature for comfortable fitting applications.We hybridized commercially available thermoplastic rubber(TPR)used in the footwear industry with un-crosslinked polycaprolactone(PCL)to create two samples,namely TP6040 and TP7030.The shape memory behavior,elasticity,and thermo-mechanical response of these rubbers were systematically investigated.The experimental results demonstrated outstanding shape memory performance,with both samples achieving shape fixity ratios(Rf)and shape recovery ratios(R_(r))exceeding 94%.TP6040 exhibited a fitting time of 80 s at body temperature(37℃),indicating a rapid response for shape fixing.The materials also showed good elasticity before and after programming,which is crucial for comfort fitting.These findings suggest that the developed shape memory thermoplastic rubber has potential applications in personalized comfort fitting products,offering advantages over traditional customization techniques in terms of efficiency and cost-effectiveness.展开更多
Electromagnetic pollution is becoming significantly serious.Therefore,it is critical to prepare the advanced electromagnetic interference(EMI)shielding materials with thinness,flexibility and high mechanical strength....Electromagnetic pollution is becoming significantly serious.Therefore,it is critical to prepare the advanced electromagnetic interference(EMI)shielding materials with thinness,flexibility and high mechanical strength.Herein,the copperbased metal-organic framework(MOF-Cu)and polyethyleneiminemodified ammonium polyphosphate(PEI-APP)were successfully synthesized.The flame-retardant thermoplastic polyurethane(TPU)composite was successfully prepared by compounding MOF-Cu and PEI-APP.The Cotton@PDA@MXene composite was fabricated via a sequential loading process of polydopamine(PDA)and MXene onto cotton fabric.Then,the multilayer TPU composites were prepared by layer-by-layer hot-pressing.The TPU/9PAPP/1MOF/C-3PM composite exhibited exceptional EMI effectiveness of 20.5 dB in X-band and 23.0 dB in K-band,exceeding commercial standards.The TPU/9P-APP/1MOF/C-3PM composite also demonstrated significantly enhanced flame retardancy.Compared with pure TPU/Cotton sample,the peak heat release rate,total heat release and total smoke release of TPU/9PAPP/1MOF/C-3PM composite decreased by 40.7%,31.1%,and 33.3%,respectively.Furthermore,the thickness of the multilayer TPU composites was only 1 mm,demonstrating excellent flexibility.As the outer encapsulation material,TPU endowed the multilayer TPU composites outstanding durability and effectively addressed the common issues of fabric abrasion and conductive filler detachment.This study provides a novel strategy for preparing flexible electromagnetic interference shielding materials with superior flame retardancy.展开更多
Adjusting the structure of the hard segment(HS)represents a key method for manipulating the mechanical properties of thermoplastic polyurethane(TPU).This study developed a novel molecular design strategy to tailor TPU...Adjusting the structure of the hard segment(HS)represents a key method for manipulating the mechanical properties of thermoplastic polyurethane(TPU).This study developed a novel molecular design strategy to tailor TPU's mechanical performance through altering the terminal diisocyanate structure of HS.The typical HDI-BDO based TPU was chosen as a model.Replacing HS's terminal HDI residues with aromatic PPDI,TODI,and MDI(the corresponding TPUs are named as 2P,2TO,and 2M,respectively)enabled broad tuning of TPU's Young's modulus while maintaining high tensile strength and elongation.Compared with linear PPDI and TODI,the bent and unsymmetrical MDI exhibits greater deviation from the central axis of the middle HDI-BDO segment,which reduces HS's capability of three-dimensionally ordered packing.Therefore,2P and 2TO show higher hydrogen bond content and crystallinity,stronger physical crosslinking network,and thus much higher Young's modulus than 2M(75.6 MPa).Besides geometric structure,π–πstacking between HS's terminal aromatic diisocyanates critically governs TPU's physical crosslinking network.In 2P,π–πstacking induces torsion of the middle HDI-BDO segment and disrupts the neighboring hydrogen bonds,leading to a dense network with fine hard blocks.In contrast,the lateral methyl groups in TODI hinderπ–πstacking,resulting in a sparse network with large hard blocks.Accordingly,2TO exhibits a higher Young's modulus(146.2 MPa)than 2P(124.0 MPa),but greater strain-rate sensitivity.展开更多
The efficient recycling of poly(ethylene terephthalate)and poly(butylene terephthalate),the most extensively produced plastics,is essential for reducing global carbon emissions and the current dependence on fossil res...The efficient recycling of poly(ethylene terephthalate)and poly(butylene terephthalate),the most extensively produced plastics,is essential for reducing global carbon emissions and the current dependence on fossil resources.However,the chemical recycling of polyesters primarily involves polymer-to-monomer and monomer-to-polymer processes,resulting in significant greenhouse gas emissions owing to significant electricity and fuel consumption.Herein,this research reports a simple and efficient one-pot polymer-to-polymer upcycling process that directly converts these two polyester wastes into biodegradable thermoplastic poly(ether ester)s using poly(tetramethylene ether)glycol(PTMG).The synthesized series of poly((ET-co-BT)-mb-PTMG)(PEBTG)exhibit a maximum tensile strength of 68 MPa,with 85%weight loss after 20 weeks in composted soil.Techno-economic analysis and life cycle assessment indicate that PEBTG is more cost-competitive and environmentally beneficial than currently existing plastics derived from fossil fuels,such as polypropylene and polybutylene adipate terephthalate.Once de-risked,the proposed upcycling strategy for polymer waste can be extended to expedite the development of a sustainable plastic economy.展开更多
The SafeAmpCase is an innovative 3D-printed solution developed to address critical challenges in transporting and storing fragile glass drug ampoules during emergencies.This study employs a multidisciplinary approach...The SafeAmpCase is an innovative 3D-printed solution developed to address critical challenges in transporting and storing fragile glass drug ampoules during emergencies.This study employs a multidisciplinary approach—integrating biomedical engineering,advanced materials science,and emergency medicine expertise—to develop a compact,durable,and user-friendly ampoule case.A key innovation lies in the strategic selection of thermoplastic polyurethane(TPU)as the material,leveraging its superior impact resistance,flexibility,and noise-damping characteristics to ensure reliability under performance in demanding real-world conditions.To optimize the 3D printing process,key parameters,including printing temperature(220-250℃),volumetric flow rate(3-20 mm^(3)/s),retraction speed(30-90 mm/s),and retraction length(0.4-1.2 mm),were systematically adjusted using calibration models.The final optimized parameters(245℃,7 mm^(3)/s,90 mm/s,and 1.2 mm)reduced production time by 43%while preserving structural integrity.American Society for Testing and Materials(ASTM)international standard drop tests confirmed the case’s exceptional impact resistance,demonstrating a 90%reduction in ampoule breakage compared to polylactic acid plus.Further refinements,guided by feedback from 25 emergency professionals,resulted in medicationspecific color coding and an enhanced locking mechanism for usability in high-pressure situations.The final SafeAmpCase model withstood 18 consecutive drop trials without ampoule breakage,confirming its robustness in field conditions.This research underscores the transformative potential of additive manufacturing in developing customized,high-performance solutions for critical healthcare applications,setting a new benchmark for biomedical device design and rapid prototyping.展开更多
The continuous improvement in patient care and recovery is driving the development of innovative materials for medical applications.Medical sutures,essential for securing implants and closing deep wounds,have evolved ...The continuous improvement in patient care and recovery is driving the development of innovative materials for medical applications.Medical sutures,essential for securing implants and closing deep wounds,have evolved to incorporate smart materials capable of responding to various stimuli.This study explores the potential of thermoresponsive sutures,made from shape memory materials,that contract upon heating to bring loose stitches closer together,promoting optimal wound closure.We developed nanocomposites based on a blend of poly(lactic acid)(PLA)and thermoplastic polyurethane(TPU)—biopolymers that inherently exhibit shape memory—enhanced with carbon nanotubes(CNT)and graphene nanoplatelets(GN)to improve mechanical performance.PLA/TPU(50/50)nanocomposites were prepared with 1 and 2 wt%GN,as well as hybrid formulations combining 1 wt%CNT with 1 or 2 wt%GN,using a twin-screw extrusion process to form filaments.These filaments were characterized through differential scanning calorimetry(DSC),field emission gun scanning electron microscopy(FEG-SEM),tensile testing,and shape memory assessments.While the PLA/TPU blend is immiscible,TPU enhances the crystallinity(X_(c))of the PLA phase,further increased by the addition of CNT and GN.FEG-SEM images indicate CNTs primarily in the PLA phase and GN in the TPU phase.PLA/TPU with 1 or 2 wt%GN showed the highest potential for suture applications,with a high elastic modulus(~1000 MPa),significant strain at break(~10%),and effective shape recovery(~20%at 55℃ for 30 min).These findings suggest that these nanocomposites can enhance suture performance with controlled shape recovery that is suitable for medical use.展开更多
The z-axis-inclined 3D printing process using short carbon fiber-reinforced thermoplastic composites offers the potential for the support-free fabrication of complex structures and theoretically unlimited extension of...The z-axis-inclined 3D printing process using short carbon fiber-reinforced thermoplastic composites offers the potential for the support-free fabrication of complex structures and theoretically unlimited extension of printed components.It has emerged as a promising approach for in-orbit manufacturing of high-performance thermoplastic composite truss structures.However,extreme conditions of the space environment,such as high vacuum and fluctuating high-low temperatures,significantly alter the heat-transfer behavior during the printing process,often resulting in dimensional inaccuracies and degraded mechanical performance.Existing process optimization strategies fail to account for the coupled effects of vacuum and thermal extremes,limiting their applicability in guiding process design under varying vacuum temperature conditions.To address this gap,this study establishes a truss3D printing experimental platform with in situ temperature-monitoring capability under ground-simulated space conditions.It systematically investigates the effects of printing speed and structural geometry on the pre-bonding surface temperature and forming quality of truss structures in high-low temperature vacuum environments.This study reveals the mechanism by which processing and structural parameters affect the component performance through their influence on the pre-bonding surface temperature and dimensional accuracy.The experimental results show that under high-temperature vacuum conditions,the pre-bonding surface temperature is relatively high,resulting in good interfacial bonding.However,increasing the printing speed reduces the forming accuracy and leads to a decline in mechanical performance.In contrast,under low-temperature vacuum conditions,where the pre-bonding surface temperatures are lower,increasing the printing speed within a specific range effectively increases the surface temperature and bonding quality,thereby improving mechanical properties.Additionally,owing to frequent path transitions,the diagonal-strut truss exhibits a lower forming accuracy and pre-bonding surface temperature than the infilling truss,resulting in inferior mechanical performance in high-low temperature vacuum environments.展开更多
Wood-polymer composites (WPC) were prepared from wood fiber and four kinds of plastics such as PE, PS, ABS, and SAN. The effects of different modifiers on the mechanical properties of the composites were studied. The ...Wood-polymer composites (WPC) were prepared from wood fiber and four kinds of plastics such as PE, PS, ABS, and SAN. The effects of different modifiers on the mechanical properties of the composites were studied. The results showed modifiers could raise the bonding strength of wood fiber with polymer and improve the mechanical properties of the composites. Different modifiers had different effects on the properties of wood-polymer composites, and comparatively the modifier of isocyanate produced a better result. Wood-polymer composite takes not only the advantages of both wood fiber and polymer, but waterproof, dimensional stability and dynamic strength are also significantly improved. Key word Wood fiber - Thermoplastic polyester - Wood-polymer composites - Modifier - Mechanical properties CLC number TB332 Document code A Foundation item: This study was supported by the Harbin Technology Tackle Key Plan (Development Research of Wood-Polymer Composites with High Wood Matrix) and by Heilongjing Nature Science Fund (Composite Mechanism Study of the Wood Polymer).Biography: XU Min (1963-), Female, Associate professor in Material Science and Engineering College, Northeast Forestry University, Harbin 150040, P. R. China.Responsible editor: Chai Ruihai展开更多
Thermoplastic starch is a kind of modified starch produced by mixing starch with additives and processing the mixture in an extruder. The mechanical properties, including tensile strength and elongation at break, biod...Thermoplastic starch is a kind of modified starch produced by mixing starch with additives and processing the mixture in an extruder. The mechanical properties, including tensile strength and elongation at break, biodegradability and rheological properties were studied. Glycerol and urea, to some extent, can both decrease the tensile strength and increase percentage elongation at break, because the former acts as a plasticizer and the latter can break down interactions among starch macromolecules. Thermoplastic starch shows thermoplasticity and its melt behaves as a pseudoplastic liquid at a low shear rate. Its biodegrading extent is slightly higher than that of native starch. The molecular weight of starch displays a decreasing tendency after thermoplastic modification.展开更多
In-situ reactive compatibilization of high-density polyethylene （HDPE）/ground tire rubber （GTR） blends by dicumyl peroxide （DCP） and HY-2045 - a kind of thermoplastic phenolic resin without catalyst was inves...In-situ reactive compatibilization of high-density polyethylene （HDPE）/ground tire rubber （GTR） blends by dicumyl peroxide （DCP） and HY-2045 - a kind of thermoplastic phenolic resin without catalyst was investigated by studying the mor-phology, stress and strain behavior, dynamic mechanical properties and crystallization performance of the blends. Scanning e-lectron microscopy （SEM） results show that there are a lot of fibrous materials distributing in the interface, which connects the dispersed phase with the matrix and obtains better interfacial strength for prominent mechanical properties. The addition of compatibilizers results in the decrease of crystallinity of the blends and the disappearance of an obvious yield phenomenon, which was proved by the differential scanning calorimeter （DSC） test and X-ray diffraction （XRD） characterization Although the crystallinity of the blends decreases,the tensile strength and tensile strain of the blends significantly increases, especially for the HDPE/GTR/DCP/HY-2045 blends, which is possibly attributed to the good compatibility of the blends owing to the in-situ interface crosslinking. In addition, it is found that the compatibilizing HDPE/GTR blends shows a higher tan^ peak temperature and a broaden transition peak for GTR phase.展开更多
基金Fujian Province science and technology office (2007F5030)(in part) National Natural Scince Foundation of China (grant 50473063)
文摘Chinese bamboo flour was chemically modified by acetylation with acetic anhydride by using trichloroacetic acid as an activation agent and the optimized condition for acetylation of bamboo flour was determined as the trichloroacetic acid amount 6.0 g per 1.5-g bamboo flour, ultrasosonication duration 40 min and the reaction time 1 h at 65℃. The composition, microstructure and thermal behavior of acetylated bamboo flour were preliminarily characterized by FT-IR, DSC and SEM etc. The acetylated bamboo flour can be molded into sheets at 130℃ and 10 MPa, indicating the modified bamboo flour possesses thermalplastic performance.
基金supported by the National Natural Science Foundation of China(51974078)the Applied Basic Research Program of Liaoning Province(2022JH2/101300002,2022JH25/10200003)the Applied Basic Research Program of Liaoning Province,and the State Key Laboratory of Metal Material for Marine Equipment and Application Project(SKLMEA-K202204).
文摘After the heavy reduction(HR)process was carried out at the solidification end of the continuous casting slab,the austenite grains were refined by recrystallization,which improved the thermoplasticity of the slab.However,the reduction in deformation during the HR process initiated stress concentration at the slab surface,and the crack risk increased.To effectively evaluate the risk of slab surface cracks under these complex conditions,the effect of the HR on the austenite recrystallization and thermoplasticity of a microalloyed slab surface was investigated by 15-pass reduction thermal simulation according to the wide and thick slab continuous casting process.The softening fraction was introduced as a global internal variable to quantitatively analyze various recrystallized re-refined grains.After the critical strain reaches the critical strain of dynamic recrystallization,a variety of recrystallization modes alternately occur.Among them,the contribution rate of dynamic crystallization to the later refinement reaches more than 50%.The contribution rates of static recrystallization and metadynamic recrystallization to grain refinement are almost the same.The thermoplasticity of the slab surface first increases and then decreases with increasing reduction pass.It was verified by transmission electron microscopy that the main reason for the decrease in thermoplasticity is that the dislocation multiplication rate increases,resulting in a sharp increase in stress and a decrease in thermoplasticity.
基金supported by the National Natural Science Foundation of China(Grant No.51174050)the Fundamental Research Project of the Ministry of Education of China (Grant No.N110402010)Liaoning Province High School Innovation Team Support Plan
文摘Through the addition of appropriate amount of Mg （0.01-0.01 5 wt%） to the stainless bearing steel Cr14Mo4, the high-temperature thermoplasticity of steel was improved. The mechanism has been uncovered that the added Mg plays an important role in refining and uniforming the carbide precipitations in the steel. It has been found that the segregation of trace Mg is the key to improve the dispersed carbide. Moreover, considerable segregation of Mg in steel during annealing was evidenced by the theoretic analysis.
文摘Concrete production often relies on natural aggregates,which can lead to resource depletion and environmental harm.In addition,improper disposal of thermoplastic waste exacerbates ecological problems.Although significant attention has recently been given to recycling various waste materials into concrete,studies specifically addressing thermoplastic recycled aggregates are still trending.This underscores the need to comprehensively review existing literature,identify research trends,and recognize gaps in understanding the mechanical performance of thermoplastic-based recycled aggregate concrete.Accordingly,this review summarizes recent investigations focused on the mechanical properties of thermoplastic-based recycled aggregate concrete,emphasizing aspects such as compressive strength,tensile behavior,modulus of elasticity,and durability characteristics.The primary aim is to consolidate scattered research findings,identify key parameters influencing mechanical behavior,and propose future research directions.Understanding the influence of recycled thermoplastic aggregates on concrete performance significantly supports sustainable construction practices by reducing dependency on virgin aggregates and mitigating environmental impacts associated with waste disposal.In addition,assessing mechanical performance contributes to confidence in the practical application,encouraging the broader adoption of thermoplastic-based recycled aggregate concrete in construction projects.Through this critical synthesis,the review guides researchers and industry practitioners toward informed decisions on the feasibility and reliability of integrating thermoplastic waste into concrete,thereby promoting sustainable infrastructure development.
基金financially supported by the National Natural Science Foundation of China(Nos.52263010 and 52372188)2023 Introduction of studying abroad talent program,Henan Provincial Key Scientific Research Project of Collegesand Universities(No.23A150038)+1 种基金Key Scientific Research Project of Education Department of Henan Province(No.22A150042)the National students'platform for innovation and entrepreneurship training program(No.201910476010).
文摘Thermoplastic polyurethane(TPU)consists of a hardsegment and a soft segment,where the former affords mechanical strength and thermalstability,while the latter provides a possibility of good ionic conductivity by promoting dissociation of ions from the lithium salt.Thus,TPU attracts a wide interest recently as a promising polymer electrolyte for solid-state lithium batteries.However,the relatively low ionic conductivity of TPU still restricts its actual applications due to the aggregation of polymer chains,which greatly reduces the dissociation of lithium salts.Herein,a strategy to address this challenge was adopted by in situ polymerization poly(ethylene glycol diacrylate)(PEGDA)in fully dispersed TPU.Hence a stretchable solid-state electrolyte(denoted as TELL and the contrast sample was denoted as TLL)with high ionic conductivity of 7.18×10^(-4) S/cm was obtained at room temperature.The Li^(+)transference number is 0.85 in Li|TELL|Li cell and can stably undergo charge-discharge cycles for 1400 h at a current density of O.1 mA/cm^(2),while the contrast sample is short-circuited after 634 h of cycling.The LiFePO_(4)|TELL|Li cell achieves a capacity retention of 78.93%after 200 cycles at 2 C.The LiFePO_(4) TLL Li cellonly gains the capacity retention of 51.9%after 50 cyclesat the same current density.So,the method adopted here may provide a new approach to realize a flexible solid-state electrolyte with high ion-conductivity.
基金supported by a grant from the Ministry of Research, Innovation and Digitization, UEFISCDI, Grant Nos. PN-IIIP2-2.1-PED-2021-1890, PN-IV-P6-6.3-SOL-2024-2-0254 and PNIV-P7-7.1-PTE-2024-0517, within PNCDI Ⅳ.
文摘This study represents an important step forward in the domain of additive manufacturing of energetic materials.It presents the successful formulation and fabrication by 3D printing of gun propellants using Fused Deposition Modeling(FDM)technology,highlighting the immense potential of this innovative approach.The use of FDM additive manufacturing technology to print gun propellants is a significant advancement due to its novel application in this field,which has not been previously reported.Through this study,the potential of FDM 3D-printing in the production of high-performance energetic composites is demonstrated,and also a new standard for manufacturability in this field can be established.The thermoplastic composites developed in this study are characterized by a notably high energetic solids content,comprising 70%hexogen(RDX)and 10%nitrocellulose(NC),which surpasses the conventional limit of 60%energetic solids typically achieved in stereolithography and light-curing 3D printing methods.The primary objective of the study was to optimize the formulation,enhance performance,and establish an equilibrium between printability and propellant efficacy.Among the three energetic for-mulations developed for 3D printing feedstock,only two were suitable for printing via the FDM tech-nique.Notably,the formulation consisting of 70%RDX,10%NC,and 20%polycaprolactone(PCL)emerged as the most advantageous option for gun propellants,owing to its exceptional processability,ease of printability,and high energetic performance.
基金the National Natural Science Foundation of China(Grant No.52203037,52103031,and 52073107)the Natural Science Foundation of Hubei Province of China(Grant No.2022CFB649)the National Key Research and Development Program of China(Grant No.2022YFC3901902).
文摘Liquid leakage of pipeline networks not only results in considerableresource wastage but also leads to environmental pollution and ecological imbalance.In response to this global issue, a bioinspired superhydrophobic thermoplastic polyurethane/carbon nanotubes/graphene nanosheets flexible strain sensor (TCGS) hasbeen developed using a combination of micro-extrusion compression molding andsurface modification for real-time wireless detection of liquid leakage. The TCGSutilizes the synergistic effects of Archimedean spiral crack arrays and micropores,which are inspired by the remarkable sensory capabilities of scorpions. This designachieves a sensitivity of 218.13 at a strain of 2%, which is an increase of 4300%. Additionally, it demonstrates exceptional durability bywithstanding over 5000 usage cycles. The robust superhydrophobicity of the TCGS significantly enhances sensitivity and stability indetecting small-scale liquid leakage, enabling precise monitoring of liquid leakage across a wide range of sizes, velocities, and compositionswhile issuing prompt alerts. This provides critical early warnings for both industrial pipelines and potential liquid leakage scenariosin everyday life. The development and utilization of bioinspired ultrasensitive flexible strain sensors offer an innovative and effectivesolution for the early wireless detection of liquid leakage.
基金UR 4370 LERMAB is supported by a grant overseen by the French National Research Agency(ANR)as part of the“Investissements d’Avenir”program(ANR-11-LABX-0002-01,Lab of Excellence ARBRE)in the frame of the project“Woodstic”ICEEL for the financial in the frame of the project“BoisPlast”(CARN 001301).
文摘Bio-based thermoplastic film from flax fiber and fatty acid(FA)was obtained using trifluoroacetic anhydride(TFAA)as an impelling agent.Different quantities of TFAA/FA,size of flax fiber,and fatty acids were applied to investigate chemical structure in relation to the mechanical properties.Decreasing the quantity of TFAA/FA by almost half from 1:4 to 1:2.5(flax to TFAA/FA)only reduces by 22%the weight percent gain(WPG)and ester content and reducing flax fiber size slightly increases the WPG and ester content.All the treatments showed sig-nificant chemical structure modification,observed by FTIR and solid CP/MAS^(13)C NMR,confirming the presence of carbonyl ester groups and alkyl chains,in relatively similar intensities.The crystallinity index(CrI)of esterified flax was evaluated by comparing the signal of solid CP/MAS^(13)C NMR in crystalline and amorphous regions and CrI was higher in esterified flax using a lower quantity of reagent and longer fatty acid.Esterified flax in a high quantity of reagent showed ductile or flexible behavior.Decreasing the reagent to 1:2.5 significantly increases the tensile strength and Young’s modulus,and decreases the elongation at break,presenting more brittle and stiff material.Using flax fiber in the original size results in slightly higher tensile strength and Young’s modulus and slightly lower elongation than milled flax.The tensile strength and Young’s modulus of stearic acid esterified flax obtained in this research were higher than myristic acid and comparable to the polyethylene plastics-LDPE and HDPE.
基金funded by the Foundation for Assistance to Innovations,under the“Student Startup”competition(agreement No.3075ΓCCC15-L/99398 dated 03 October 2024).
文摘The use of wood-polymer composites(WPC)based on a polymer matrix and wood filler is a modern,environmentally friendly direction in material science.However,untreated wood filler exhibits poor adhesion to hydrophobic polymers due to its hydrophilic lignocellulose fibers.To address this,ozone treatment is employed to enhance compatibility,reduce water absorption,and regulate biodegradation rates.This study investigates the hypothesis that ozone modification of wood filler improves adhesion to thermoplastic starch,thereby enhancing the physico-mechanical properties and controlled biodegradation of WPCs under compost conditions.A compre-hensive analysis was conducted on composites containing untreated and ozonated wood flour,focusing on tensile strength,bending resistance,impact strength,and biodegradation kinetics.Results showed significant improvements in mechanical properties for modified composites:tensile strength increased by 20%-25%,bending resistance by 15%-30%,and impact strength by 15%-20% compared to untreated samples.The optimal composition identified contained 70% ozonated wood flour and 30% thermoplastic starch(70WF/30P),demonstrating excellent mechanical strength(flexural strength of 18-22MPa),complete biodegradation within 140 days,and operational stability.The study revealed correlations between surface modification,interphase interaction,and biodegradation kinetics,advancing fundamental knowledge of lignocellulosic filler modification methods.These findings are crucial for developing eco-friendly composite materials with applications in biodegradable packaging and agricultural products,offering both scientific insights and practical solutions for sustainable material development.
基金supported by the Aeronautical Science Foundation of China(Grant Nos.2024Z009052003,20230038052001 and 20230015052002)the Third Batch of Science and Technology Plan Projects in Changzhou City in 2023(Applied Basic Research,Grant No.CJ20230080).
文摘This paper presents the development of a thermoplastic shape memory rubber that can be programmed at human body temperature for comfortable fitting applications.We hybridized commercially available thermoplastic rubber(TPR)used in the footwear industry with un-crosslinked polycaprolactone(PCL)to create two samples,namely TP6040 and TP7030.The shape memory behavior,elasticity,and thermo-mechanical response of these rubbers were systematically investigated.The experimental results demonstrated outstanding shape memory performance,with both samples achieving shape fixity ratios(Rf)and shape recovery ratios(R_(r))exceeding 94%.TP6040 exhibited a fitting time of 80 s at body temperature(37℃),indicating a rapid response for shape fixing.The materials also showed good elasticity before and after programming,which is crucial for comfort fitting.These findings suggest that the developed shape memory thermoplastic rubber has potential applications in personalized comfort fitting products,offering advantages over traditional customization techniques in terms of efficiency and cost-effectiveness.
基金supported by the National Natural Science Foundation of China(No.52173070).
文摘Electromagnetic pollution is becoming significantly serious.Therefore,it is critical to prepare the advanced electromagnetic interference(EMI)shielding materials with thinness,flexibility and high mechanical strength.Herein,the copperbased metal-organic framework(MOF-Cu)and polyethyleneiminemodified ammonium polyphosphate(PEI-APP)were successfully synthesized.The flame-retardant thermoplastic polyurethane(TPU)composite was successfully prepared by compounding MOF-Cu and PEI-APP.The Cotton@PDA@MXene composite was fabricated via a sequential loading process of polydopamine(PDA)and MXene onto cotton fabric.Then,the multilayer TPU composites were prepared by layer-by-layer hot-pressing.The TPU/9PAPP/1MOF/C-3PM composite exhibited exceptional EMI effectiveness of 20.5 dB in X-band and 23.0 dB in K-band,exceeding commercial standards.The TPU/9P-APP/1MOF/C-3PM composite also demonstrated significantly enhanced flame retardancy.Compared with pure TPU/Cotton sample,the peak heat release rate,total heat release and total smoke release of TPU/9PAPP/1MOF/C-3PM composite decreased by 40.7%,31.1%,and 33.3%,respectively.Furthermore,the thickness of the multilayer TPU composites was only 1 mm,demonstrating excellent flexibility.As the outer encapsulation material,TPU endowed the multilayer TPU composites outstanding durability and effectively addressed the common issues of fabric abrasion and conductive filler detachment.This study provides a novel strategy for preparing flexible electromagnetic interference shielding materials with superior flame retardancy.
基金financially supported by the CAS Project for Young Scientists in Basic Research(No.YSBR-023)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.Y2022068)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDC06020301)。
文摘Adjusting the structure of the hard segment(HS)represents a key method for manipulating the mechanical properties of thermoplastic polyurethane(TPU).This study developed a novel molecular design strategy to tailor TPU's mechanical performance through altering the terminal diisocyanate structure of HS.The typical HDI-BDO based TPU was chosen as a model.Replacing HS's terminal HDI residues with aromatic PPDI,TODI,and MDI(the corresponding TPUs are named as 2P,2TO,and 2M,respectively)enabled broad tuning of TPU's Young's modulus while maintaining high tensile strength and elongation.Compared with linear PPDI and TODI,the bent and unsymmetrical MDI exhibits greater deviation from the central axis of the middle HDI-BDO segment,which reduces HS's capability of three-dimensionally ordered packing.Therefore,2P and 2TO show higher hydrogen bond content and crystallinity,stronger physical crosslinking network,and thus much higher Young's modulus than 2M(75.6 MPa).Besides geometric structure,π–πstacking between HS's terminal aromatic diisocyanates critically governs TPU's physical crosslinking network.In 2P,π–πstacking induces torsion of the middle HDI-BDO segment and disrupts the neighboring hydrogen bonds,leading to a dense network with fine hard blocks.In contrast,the lateral methyl groups in TODI hinderπ–πstacking,resulting in a sparse network with large hard blocks.Accordingly,2TO exhibits a higher Young's modulus(146.2 MPa)than 2P(124.0 MPa),but greater strain-rate sensitivity.
基金supported by grants from the National Research Foundation of Korea(NRF),funded by the Korean government(RS-2024-00408795 and RS-2024-00466473).
文摘The efficient recycling of poly(ethylene terephthalate)and poly(butylene terephthalate),the most extensively produced plastics,is essential for reducing global carbon emissions and the current dependence on fossil resources.However,the chemical recycling of polyesters primarily involves polymer-to-monomer and monomer-to-polymer processes,resulting in significant greenhouse gas emissions owing to significant electricity and fuel consumption.Herein,this research reports a simple and efficient one-pot polymer-to-polymer upcycling process that directly converts these two polyester wastes into biodegradable thermoplastic poly(ether ester)s using poly(tetramethylene ether)glycol(PTMG).The synthesized series of poly((ET-co-BT)-mb-PTMG)(PEBTG)exhibit a maximum tensile strength of 68 MPa,with 85%weight loss after 20 weeks in composted soil.Techno-economic analysis and life cycle assessment indicate that PEBTG is more cost-competitive and environmentally beneficial than currently existing plastics derived from fossil fuels,such as polypropylene and polybutylene adipate terephthalate.Once de-risked,the proposed upcycling strategy for polymer waste can be extended to expedite the development of a sustainable plastic economy.
基金Open access funding provided by Ben-Gurion University.
文摘The SafeAmpCase is an innovative 3D-printed solution developed to address critical challenges in transporting and storing fragile glass drug ampoules during emergencies.This study employs a multidisciplinary approach—integrating biomedical engineering,advanced materials science,and emergency medicine expertise—to develop a compact,durable,and user-friendly ampoule case.A key innovation lies in the strategic selection of thermoplastic polyurethane(TPU)as the material,leveraging its superior impact resistance,flexibility,and noise-damping characteristics to ensure reliability under performance in demanding real-world conditions.To optimize the 3D printing process,key parameters,including printing temperature(220-250℃),volumetric flow rate(3-20 mm^(3)/s),retraction speed(30-90 mm/s),and retraction length(0.4-1.2 mm),were systematically adjusted using calibration models.The final optimized parameters(245℃,7 mm^(3)/s,90 mm/s,and 1.2 mm)reduced production time by 43%while preserving structural integrity.American Society for Testing and Materials(ASTM)international standard drop tests confirmed the case’s exceptional impact resistance,demonstrating a 90%reduction in ampoule breakage compared to polylactic acid plus.Further refinements,guided by feedback from 25 emergency professionals,resulted in medicationspecific color coding and an enhanced locking mechanism for usability in high-pressure situations.The final SafeAmpCase model withstood 18 consecutive drop trials without ampoule breakage,confirming its robustness in field conditions.This research underscores the transformative potential of additive manufacturing in developing customized,high-performance solutions for critical healthcare applications,setting a new benchmark for biomedical device design and rapid prototyping.
基金This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoalde Nível Superior-Brasil(CAPES)-Finance Code 001.
文摘The continuous improvement in patient care and recovery is driving the development of innovative materials for medical applications.Medical sutures,essential for securing implants and closing deep wounds,have evolved to incorporate smart materials capable of responding to various stimuli.This study explores the potential of thermoresponsive sutures,made from shape memory materials,that contract upon heating to bring loose stitches closer together,promoting optimal wound closure.We developed nanocomposites based on a blend of poly(lactic acid)(PLA)and thermoplastic polyurethane(TPU)—biopolymers that inherently exhibit shape memory—enhanced with carbon nanotubes(CNT)and graphene nanoplatelets(GN)to improve mechanical performance.PLA/TPU(50/50)nanocomposites were prepared with 1 and 2 wt%GN,as well as hybrid formulations combining 1 wt%CNT with 1 or 2 wt%GN,using a twin-screw extrusion process to form filaments.These filaments were characterized through differential scanning calorimetry(DSC),field emission gun scanning electron microscopy(FEG-SEM),tensile testing,and shape memory assessments.While the PLA/TPU blend is immiscible,TPU enhances the crystallinity(X_(c))of the PLA phase,further increased by the addition of CNT and GN.FEG-SEM images indicate CNTs primarily in the PLA phase and GN in the TPU phase.PLA/TPU with 1 or 2 wt%GN showed the highest potential for suture applications,with a high elastic modulus(~1000 MPa),significant strain at break(~10%),and effective shape recovery(~20%at 55℃ for 30 min).These findings suggest that these nanocomposites can enhance suture performance with controlled shape recovery that is suitable for medical use.
基金supported by National Key Research and Development Program of China(Grant No.2023YFB4605301)the National Natural Science Foundation of China(Grant No.52130506)。
文摘The z-axis-inclined 3D printing process using short carbon fiber-reinforced thermoplastic composites offers the potential for the support-free fabrication of complex structures and theoretically unlimited extension of printed components.It has emerged as a promising approach for in-orbit manufacturing of high-performance thermoplastic composite truss structures.However,extreme conditions of the space environment,such as high vacuum and fluctuating high-low temperatures,significantly alter the heat-transfer behavior during the printing process,often resulting in dimensional inaccuracies and degraded mechanical performance.Existing process optimization strategies fail to account for the coupled effects of vacuum and thermal extremes,limiting their applicability in guiding process design under varying vacuum temperature conditions.To address this gap,this study establishes a truss3D printing experimental platform with in situ temperature-monitoring capability under ground-simulated space conditions.It systematically investigates the effects of printing speed and structural geometry on the pre-bonding surface temperature and forming quality of truss structures in high-low temperature vacuum environments.This study reveals the mechanism by which processing and structural parameters affect the component performance through their influence on the pre-bonding surface temperature and dimensional accuracy.The experimental results show that under high-temperature vacuum conditions,the pre-bonding surface temperature is relatively high,resulting in good interfacial bonding.However,increasing the printing speed reduces the forming accuracy and leads to a decline in mechanical performance.In contrast,under low-temperature vacuum conditions,where the pre-bonding surface temperatures are lower,increasing the printing speed within a specific range effectively increases the surface temperature and bonding quality,thereby improving mechanical properties.Additionally,owing to frequent path transitions,the diagonal-strut truss exhibits a lower forming accuracy and pre-bonding surface temperature than the infilling truss,resulting in inferior mechanical performance in high-low temperature vacuum environments.
基金Supported by the Harbin Technology Tackle Key Plan (Development Research of Wood-Polymer Composites with High Wood Matrix) and by Heilongjing Nature Science Fund (Composite Mechanism Study of the Wood Polymer).
文摘Wood-polymer composites (WPC) were prepared from wood fiber and four kinds of plastics such as PE, PS, ABS, and SAN. The effects of different modifiers on the mechanical properties of the composites were studied. The results showed modifiers could raise the bonding strength of wood fiber with polymer and improve the mechanical properties of the composites. Different modifiers had different effects on the properties of wood-polymer composites, and comparatively the modifier of isocyanate produced a better result. Wood-polymer composite takes not only the advantages of both wood fiber and polymer, but waterproof, dimensional stability and dynamic strength are also significantly improved. Key word Wood fiber - Thermoplastic polyester - Wood-polymer composites - Modifier - Mechanical properties CLC number TB332 Document code A Foundation item: This study was supported by the Harbin Technology Tackle Key Plan (Development Research of Wood-Polymer Composites with High Wood Matrix) and by Heilongjing Nature Science Fund (Composite Mechanism Study of the Wood Polymer).Biography: XU Min (1963-), Female, Associate professor in Material Science and Engineering College, Northeast Forestry University, Harbin 150040, P. R. China.Responsible editor: Chai Ruihai
文摘Thermoplastic starch is a kind of modified starch produced by mixing starch with additives and processing the mixture in an extruder. The mechanical properties, including tensile strength and elongation at break, biodegradability and rheological properties were studied. Glycerol and urea, to some extent, can both decrease the tensile strength and increase percentage elongation at break, because the former acts as a plasticizer and the latter can break down interactions among starch macromolecules. Thermoplastic starch shows thermoplasticity and its melt behaves as a pseudoplastic liquid at a low shear rate. Its biodegrading extent is slightly higher than that of native starch. The molecular weight of starch displays a decreasing tendency after thermoplastic modification.
文摘In-situ reactive compatibilization of high-density polyethylene （HDPE）/ground tire rubber （GTR） blends by dicumyl peroxide （DCP） and HY-2045 - a kind of thermoplastic phenolic resin without catalyst was investigated by studying the mor-phology, stress and strain behavior, dynamic mechanical properties and crystallization performance of the blends. Scanning e-lectron microscopy （SEM） results show that there are a lot of fibrous materials distributing in the interface, which connects the dispersed phase with the matrix and obtains better interfacial strength for prominent mechanical properties. The addition of compatibilizers results in the decrease of crystallinity of the blends and the disappearance of an obvious yield phenomenon, which was proved by the differential scanning calorimeter （DSC） test and X-ray diffraction （XRD） characterization Although the crystallinity of the blends decreases,the tensile strength and tensile strain of the blends significantly increases, especially for the HDPE/GTR/DCP/HY-2045 blends, which is possibly attributed to the good compatibility of the blends owing to the in-situ interface crosslinking. In addition, it is found that the compatibilizing HDPE/GTR blends shows a higher tan^ peak temperature and a broaden transition peak for GTR phase.
