In this work, a series of high performance bio-based polyurethanes（bio-PUs） were synthesized from polylactide（PLA）-based diols, different diisocyanates（TDI, MDI, HDI, IPDI） and chain extender 1,4-butanediol, in ...In this work, a series of high performance bio-based polyurethanes（bio-PUs） were synthesized from polylactide（PLA）-based diols, different diisocyanates（TDI, MDI, HDI, IPDI） and chain extender 1,4-butanediol, in which different soft and hard segments are used to adjust their transition temperatures and mechanical properties. Poly（lactide-co-caprolactone）copolymer diols（co-PLAols） instead of PLA diols as the soft segment improved the thermal stability and mechanical properties of the synthesized bio-PUs. Among them, MDI-based bio-PUs have the highest T_g（43.8 °C）, tensile strength（23.5 MPa） and modulus（380.8 MPa）, while HDI-based bio-PUs have the lowest T_g（21.4 °C） and highest elongation at break（580%）. Especially, the bio-PUs synthesized from co-PLAols and MDI demonstrate better mechanical properties,closed to petroleum-based commodities. Furthermore, the obtained bio-PUs display good shape memory properties at body temperature and cytocompatibility. Therefore, these bio-PUs are promising for applications in biomedical fields.展开更多
Elastic bio-based waterproof and breathable membranes(EBWBMs) allow the passage of water vapor effectively and resist the penetration of liquid water,making it ideal for use under extreme conditions.In this study,we u...Elastic bio-based waterproof and breathable membranes(EBWBMs) allow the passage of water vapor effectively and resist the penetration of liquid water,making it ideal for use under extreme conditions.In this study,we used a facile strategy to design the bio-based polyurethane(PU) nanofibrous membranes with the nanoscale porous structure to provide the membranes with high waterproof and breathable performances.The optimization of nanofibrous membrane formation was accomplished by controlling the relative ambient humidity to modulate the cooperating effects of charge dissipation and non-solvent-induced phase separation.The obtained EBWBMs showed multiple functional properties,with a hydrostatic pressure of 86.41 kPa and a water vapor transmission(WVT) rate of 10.1 kg·m^(-2)·d^(-1).After 1 000 cycles of stretching at 40% strain,the EBWBMs retained over 59% of the original maximum stress and exhibited an ideal elasticity recovery ratio of 85%.Besides,even after 80% deformation,the EBWBMs still maintained a hydrostatic pressure of 30.65 kPa and a WVT rate of 13.6 kg·m^(-2)·d^(-1),suggesting that bio-based PU nanofibrous membranes could be used for protection under extreme conditions.展开更多
Through systematical experiment design, the physical blowing agent(PBA) mass loss of bio-based polyurethane rigid foam(PURF)in the foaming process was measured and calculated in this study, and different eco-friendly ...Through systematical experiment design, the physical blowing agent(PBA) mass loss of bio-based polyurethane rigid foam(PURF)in the foaming process was measured and calculated in this study, and different eco-friendly PBA mass losses were measured quantitatively for the first time. The core of the proposed method is to add water to replace the difference, and this method has a high fault tolerance rate for different foaming forms of foams. The method was proved to be stable and reliable through the standard deviations σ1and σ2for R1(ratio of the PBA mass loss to the material total mass except the PBA) and R2(ratio of the PBA mass loss to the PBA mass in the material total mass) in parallel experiments. It can be used to measure and calculate the actual PBA mass loss in the foaming process of both bio-based and petroleumbased PURF. The results show that the PBA mass loss in PURF with different PBA systems is controlled by its initial mass content of PBA in PU materials ω. The main way for PBA to dissipate into the air is evaporation/escape along the upper surface of foam. This study further reveals the mechanism of PBA mass loss: the evaporation/escape of PBA along the upper surface of foam is a typical diffusion behavior. Its spread power comes from the difference between the chemical potential of PBA in the interface layer and that in the outside air. For a certain PURF system, R1has approximately linear relationship with the initial mass content of PBA in PU materials ω, which can be expressed by the functional relationship R1= kω, where k is a variable related to PBA’s own attributes.展开更多
Irregular articular cartilage injury is a common type of joint trauma,often resulting from intense impacts and other factors that lead to irregularly shaped wounds,the limited regenerative capacity of cartilage and th...Irregular articular cartilage injury is a common type of joint trauma,often resulting from intense impacts and other factors that lead to irregularly shaped wounds,the limited regenerative capacity of cartilage and the mismatched shape of the scaffods have contributed to unsatisfactory therapeutic outcomes.While injectable materials are a traditional solution to adapt to irregular cartilage defects,they have limitations,and injectable materials often lack the porous microstructures favorable for the rapid proliferation of cartilage cells.In this study,an injectable porous polyurethane scaffold named PU-BDO-Gelatin-Foam(PUBGF)was prepared.After injection into cartilage defects,PUBGF forms in situ at the site of the defect and exhibits a dynamic microstructure during the initial two weeks.This dynamic microstructure endows the scaffold with the ability to retain substances within its interior,thereby enhancing its capacity to promote chondrogenesis.Furthermore,the chondral repair efficacy of PUBGF was validated by directly injecting it into rat articular cartilage injury sites.The injectable PUBGF scaffold demonstrates a superior potential for promoting the repair of cartilage defects when compared to traditional porous polyurethane scaffolds.The substance retention ability of this injectable porous scaffold makes it a promising option for clinical applications.展开更多
To alleviate the pressure on the petrochemical industry and address environmental concerns,the utilization of polyurethane(PU)derived from castor oil(CO)(as an ester polyol replacement of petrochemicalbased materials)...To alleviate the pressure on the petrochemical industry and address environmental concerns,the utilization of polyurethane(PU)derived from castor oil(CO)(as an ester polyol replacement of petrochemicalbased materials)has garnered significant attention in recent decades.Extending the service life of materials requires imparting self-healing properties to vegetable oil-based polymers,an aspect that has received limited attention in current studies.However,low self-healing efficiency still poses a significant challenge,and non-conductivity also remains an obstacle in current research,crucial for their application in electronic devices.In this work,we present the first series of electrically self-healing biopolymer composites constructed by incorporating carbon nanotube(CNT)networks into crosslinked castor oil-based polyurethane(BPU)through a simple curing process.These materials address the challenges mentioned above and exhibit improved mechanical,electrical,and self-healing capabilities compared to other biobased self-healing materials.The resulting BPU/CNT composite demonstrated exceptional repeated selfhealing capacity,restoring both mechanical properties and electrical performance even after experiencing severe mechanical damage.Notably,this composite served as a conductive substrate in flexible solid-state supercapacitor(FSSC)devices.Consequently,the FSSC derived from the composite conductive substrate achieved an impressive 92.4%self-healing efficiency even after undergoing 7 cutting/healing cycles.The device remained virtually unchanged even after being bent at a 180°angle with a bending radius of 1.6 mm,indicating excellent repeatability and durability.The exceptional self-healing ability,with∼98%electrical recovery at 100℃for 70 s and 93%at 80℃after 6 min,of these composites was attributed to the synergistic interactions of the dynamic exchange reactions of disulfide bonds and dense hydrogen bonds within the BPU matrix,which provide a reversible dynamic polymer network.The healing efficiency of these dynamic bonds was evaluated by adjusting the composition ratio of the long linear chain of pTHF in hybrid polyols of the crosslinked polymer network.Overall,this work highlights a series of green,simple,and highly efficient self-healing polymer composites derived from renewable castor oil,and it establishes an essential framework for future sustainable polymer composite design.展开更多
The Publisher regrets that the Graphical Abstract(see below)was missed due to a transmittal problem,and it was not published with the original article.
Cryogenic insulation material rigid polyurethane(PU)foams were developed using bio-based and recycled feedstock.Polyols obtained from tall oil fatty acids produced as a side stream of wood biomass pulping and recycled...Cryogenic insulation material rigid polyurethane(PU)foams were developed using bio-based and recycled feedstock.Polyols obtained from tall oil fatty acids produced as a side stream of wood biomass pulping and recycled polyethylene terephthalate were used to develop rigid PU foam formulations.The 4th generation physical blowing agents with low global warming potential and low ozone depletion potential were used to develop rigid PU foam cryogenic insulation with excellent mechanical and thermal properties.Obtained rigid PU foams had a thermal conductivity coefficient as low as 0.0171 W/m·K and an apparent density of 37-40 kg/m^(3).The developed rigid PU foams had anisotropic compression strength properties,which were higher parallel to the foaming direction.Moreover,the compression strength was also influenced by the type of applied bio-based polyol.The bio-based polyols with higher OH group functionality delivered higher crosslinking density of polymer matrix;thus,the mechanical properties were also higher.The mechanical strength of the foams increased when materials were tested at liquid nitrogen temperature due to the stiffening of the polymer matrix.The thermal properties of the developed materials were determined using differential scanning calorimetry,dynamic mechanical analysis,and thermogravimetric analysis methods.Lastly,the developed rigid PU foams had good adhesion to the aluminium substrate before and after applying cyroshock and an excellent safety coefficient of 4-5.Rigid PU foams developed using Solstice LBA delivered adhesion strength of~0.5 MPa and may be considered for application as cryogenic insulation in the aerospace industry.展开更多
PU,or polyurethane,features a repeating urethane group(-NH-COO-)in its molecular structure.Traditionally,PUs are synthesized from isocyanate and polyol compounds derived from fossil resources through polymerization re...PU,or polyurethane,features a repeating urethane group(-NH-COO-)in its molecular structure.Traditionally,PUs are synthesized from isocyanate and polyol compounds derived from fossil resources through polymerization reactions.The depletion of fossil fuels and the increasing climate problems call for the expansion of more renewable sources of chemicals,such as modern biomass.However,the conversion of biomass into chemicals is challenging due to the inherent molecular complexity of its composition.In recent years,advances in green chemistry have led researchers to focus on developing bio-based polyurethanes by sourcing polyols,isocyanates,and chain extender precursors from biological materials.This paper focuses on the preparation of polyols,non-isocyanates and bio-based chain extenders from bio-based materials such as vegetable oils,lignin,sugars,and rosin.The synthetic routes and properties of several bio-based polyurethane materials are analyzed.Additionally,it discusses the current status,future challenges,and potential applications of bio-based polyurethane materials across various fields.展开更多
This study identified castor oil and phosphate ester as effective retarders through setting time,tensile,and flexural tests,and determined their optimal dosages.The mechanism by which phosphate ester affects the setti...This study identified castor oil and phosphate ester as effective retarders through setting time,tensile,and flexural tests,and determined their optimal dosages.The mechanism by which phosphate ester affects the setting time of polyurethane was further investigated using molecular dynamics simulations.Fourier transform infrared spectroscopy was also employed to systematically study the physical and chemical interactions between phosphate esters and polyurethane materials.The results demonstrate that a 1%concentration of phosphate ester provides the most effective retarding effect with minimal impact on the strength of polyurethane.When phosphate ester is added to the B component of the two-component polyurethane system,its interaction energy with component A decreases,as do the diffusion coefficient and aggregation degree of component B on the surface of component A.This reduction in interaction slows the setting time.Additionally,the addition of phosphate ester to polyurethane leads to the disappearance or weakening of functional groups,indicating competitive interactions within the phosphate ester components that inhibit the reaction rate.展开更多
Shotcrete is one of the common solutions for shallow sliding.It works by forming a protective layer with high strength and cementing the loose soil particles on the slope surface to prevent shallow sliding.However,the...Shotcrete is one of the common solutions for shallow sliding.It works by forming a protective layer with high strength and cementing the loose soil particles on the slope surface to prevent shallow sliding.However,the solidification time of conventional cement paste is long when shotcrete is used to treat cohesionless soil landslide.The idea of reinforcing slope with polyurethane solidified soil(i.e.,mixture of polyurethane and sand)was proposed.Model tests and finite element analysis were carried out to study the effectiveness of the proposed new method on the emergency treatment of cohesionless soil landslide.Surcharge loading on the crest of the slope was applied step by step until landslide was triggered so as to test and compare the stability and bearing capacity of slope models with different conditions.The simulated slope displacements were relatively close to the measured results,and the simulated slope deformation characteristics were in good agreement with the observed phenomena,which verifies the accuracy of the numerical method.Under the condition of surcharge loading on the crest of the slope,the unreinforced slope slid when the surcharge loading exceeded 30 k Pa,which presented a failure mode of local instability and collapse at the shallow layer of slope top.The reinforced slope remained stable even when the surcharge loading reached 48 k Pa.The displacement of the reinforced slope was reduced by more than 95%.Overall,this study verifies the effectiveness of polyurethane in the emergency treatment of cohesionless soil landslide and should have broad application prospects in the field of geological disasters concerning the safety of people's live.展开更多
Doping perylene diimide(PDI)into a polymer matrix is a simple strategy to prepare near-infrared(NIR)reflective materials,but the mechanical properties and NIR reflectance properties are significantly compromised due t...Doping perylene diimide(PDI)into a polymer matrix is a simple strategy to prepare near-infrared(NIR)reflective materials,but the mechanical properties and NIR reflectance properties are significantly compromised due to macro-phase separation.In this study,a novel polymer(denoted as PU-PDI)with intrinsic NIR reflective proper⁃ties was synthesized by covalent incorporation of PDI units into polyurethane chains.Its photophysical characteris⁃tics,mechanical property and NIR reflectance property are investigated in detail.The results show that covalent in⁃corporation reduces the severe aggregation of PDI units,thereby endows PU-PDI with excellent mechanical property.The elongation at break of PU-PDI can reach more than 700%,and the breaking strength is 34.11 MPa.Moreover,compared to the blending system,PU-PDI possesses enhanced NIR reflection ability due to the better dispersion of PDI units.展开更多
Dear Editor,Environmental pollution from microplastics(MPs)has recently gained attention as a potential environmental hazard(Chia et al.,2021).Agricultural soils could contain more MPs than the ocean by 2050 because m...Dear Editor,Environmental pollution from microplastics(MPs)has recently gained attention as a potential environmental hazard(Chia et al.,2021).Agricultural soils could contain more MPs than the ocean by 2050 because more MPs enter the soil than the ocean(Nizzetto et al.,2016).The carbon(C)-C backbone of degradation-resistant MPs provides considerable stability in the soil,where they can remain for several decades(Iqbal et al.,2023).展开更多
Boron adsorbents with high adsorption capacities have long been a focus of research for a long time.This study used small molecular polyols with different hydroxyl groups as functional monomers and as end-capping agen...Boron adsorbents with high adsorption capacities have long been a focus of research for a long time.This study used small molecular polyols with different hydroxyl groups as functional monomers and as end-capping agents,functional dendritic polyurethanes with nano structure were successfully prepared by one-pot method.The single molecule size and surface morphology were characterized by dynamic light scattering,transmission electron microscopy and scanning electron microscopy,and the molecular size in the dry state was 11 to 18 nm.The prepared materials were used as the boron adsorbents,and the effects of pH,time,boron solution concentration and temperature on the adsorption were studied.The results showed that the capacity of adsorbed boron could reach 110-130 mg·g^(-1).Adsorption was a homogeneous monolayer adsorption controlled by chemisorption,and adsorption thermodynamics showed that was a spontaneous endothermic process.Adsorption behavior was best described by the pseudo-second-order kinetic model and the Langmuir isotherm.This study also showed that it was difficult for ortho/meta-hydroxyl groups to chelate with H_(3)BO_(3) and other polyborates,and the chelates mainly had good chelating properties with B(OH)_(4)^(-),and the chelates formed had large steric hindrance.At the same time,increasing the number of hydroxyl groups of functional monomers was beneficial to increase the adsorption capacity of materials.In addition,the cyclic adsorption/desorption experiments showed that DPUs have good cyclic stability.At the same time,the adsorption results of the original salt lake brine showed that other metal ions in the brine had little effect on the adsorption of boron,and the adsorption capacity was as high as52.93 mg·g^(-1),and the maximum adsorption capacity was obtained by Adams-Bohart model to58.80 mg·g^(-1).The outstanding selectivity and adsorption capacity of these materials have broad potential application,and are expected to be used for the efficient adsorption and removal in boroncontaining water bodies.展开更多
The demand for energy-efficient and environmental-friendly power grid construction has made the exploitation of bio-based electrical epoxy resins with excellent properties increasingly important.This work developed th...The demand for energy-efficient and environmental-friendly power grid construction has made the exploitation of bio-based electrical epoxy resins with excellent properties increasingly important.This work developed the bio-based electrotechnical epoxy resins based on magnolol.High-performance epoxy resin(DGEMT)with a double crosslinked points and its composites(Al_(2)O_(3)/DGEMT)were obtained taking advantages of the two bifunctional groups(allyl and phenolic hydroxyl groups)of magnolol.Benefitting from the distinctive structure of DGEMT,the Al_(2)O_(3)/DGEMT composites exhibited the advantages of intrinsically high thermal conductivity,high insulation,and low dielectric loss.The AC breakdown strength and thermal conductivity of Al_(2)O_(3)/DGEMT composites were 35.5 kV/mm and 1.19 W·m-1·K-1,respectively,which were 15.6%and 52.6%higher than those of petroleum-based composites(Al_(2)O_(3)/DGEBA).And its dielectric loss tanδ=0.0046 was 20.7%lower than that of Al_(2)O_(3)/DGEBA.Furthermore,the mechanical,thermal and processing properties of Al_(2)O_(3)/DGEMT are fully comparable to those of Al_(2)O_(3)/DGEBA.This work confirms the feasibility of manufacturing environmentally friendly power equipment using bio-based epoxy resins,which has excellent engineering applications.展开更多
Bio-polyol is considered as a core material to synthesize eco-friendly polyurethane products.However,one of the popular bio-polyols,polytrimethylene ether glycol(PO3G),is reluctant to crystallize and therefore exhibit...Bio-polyol is considered as a core material to synthesize eco-friendly polyurethane products.However,one of the popular bio-polyols,polytrimethylene ether glycol(PO3G),is reluctant to crystallize and therefore exhibits a cold crystallization behavior.This abnormal behavior causes unstable mechanical properties at low-temperature and limits its applications in shape memory devices where crystallization is an essential mechanism.To analyze the unusual phenomenon,we compared different ether polyols focusing on symmetry characteristics and the evenodd effect of carbon backbones.It is found that PO3G has a slow crystallization rate because its ether linkages require specific chain arrangement for attractive interactions.Consequently,a thermal learning mechanism is developed to restore the normal crystallization behavior of elastomers synthesized from the bio-polyol.Repetitive heating and cooling cycles with high-temperature annealing induce urethane exchange reaction and reconstruct the chain orientations for fast crystallization.Results suggest the degree of crystallizations in polyurethane elastomer can be precisely controlled by introducing repetitive thermal treatments to enhance the potential applications of bio-polyols in polymer industries.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
Due to the limited regeneration capacity of myocardial tissue after infarction,designing tissue engineering scaffolds are in demand.In the present study,electrospun nanofibrous scaffolds were made out of polyurethane,...Due to the limited regeneration capacity of myocardial tissue after infarction,designing tissue engineering scaffolds are in demand.In the present study,electrospun nanofibrous scaffolds were made out of polyurethane,collagen and gold nanoparticles with random and aligned nanofiber morphologies.The nanoparticles were green-synthesized using saffron extract.Nanoparticle characterizations with UV-Vis.spectroscopy and DLS illustrated theoretical and hydrodynamic diameters of around 7 and 13 nm,respectively,having zeta potential of−37 mV.SEM and TEM micrographs showed the morphology and diameters of obtained nanofibers.Also,further characterization were done by ATR-FTIR,XRD and TGA investigations and degradation studies.Contact angle measurements showed hydrophilic nature of the scaffolds(59±0.6°for aligned PU/Col/Au50 nanofibers compared to 120±2.6°for random PU nanofibers).Mechanical testing demonstrated appropriate tensile properties of the scaffolds for cardiac tissue engineering(Young’s modulus:1.53±0.07 MPa for aligned PU/Col/Au50 nanofibers compared to 0.4±0.05 MPa for random PU nanofibers).Finally,alamar blue assay revealed proper survival of the cells of HUVEC cell line on the prepared scaffolds,where the highest percentages were observed for random and aligned PU/Col/Au50 nanofibers.According to the findings,the fabricated PU/Col/AuNPs nanofibrous scaffolds could be considered as potential cardiac patches.展开更多
Incorporation of acetal groups in the backbone is a potent strategy to create polymers that are cleavable or degradable under acidic conditions.We report here an in-depth study on the ring-closing-opening copolymeriza...Incorporation of acetal groups in the backbone is a potent strategy to create polymers that are cleavable or degradable under acidic conditions.We report here an in-depth study on the ring-closing-opening copolymerization of o-phthalaldehyde(OPA)and epoxide using Lewis pair type two-component organocatalysts for producing acetal-functionalized polyether and polyurethane.Notably,triethylborane as the Lewis acid,in comparison with tri(n-butyl)borane,more effectively enhances the polymerization activity by mitigating borane-induced reduction of the aldehyde group into extra initiating(borinic ester)species.Density functional theory(DFT)calculations present comparable energy barriers of OPA-epoxide cross-propagation and epoxide self-propagation,which is consistent with the experimental finding that an alternating-rich copolymer comprising mostly OPA-epoxide units but also epoxide-epoxide linkages is produced.In particular,when epoxide is added in a large excess,the product becomes a polyether containing acetal functionalities in the central part of the backbone and thus being convertible into polyurethane with refined acid degradability.展开更多
By investigating the performance characteristics of the bio-based surfactant 8901A,a composite decontamination and injection system was developed using 8901A as the primary agent,tailored for application in low-permea...By investigating the performance characteristics of the bio-based surfactant 8901A,a composite decontamination and injection system was developed using 8901A as the primary agent,tailored for application in low-permeability and heavy oil reservoirs under varying temperature conditions.The results demonstrate that this system effectively reduces oil–water interfacial tension,achieving an ultra-low interfacial tension state.The static oil washing efficiency of oil sands exceeds 85%,the average pressure reduction rate reaches 21.55%,and the oil recovery rate improves by 13.54%.These enhancements significantly increase the system’s ability to dissolve oilbased blockages,thereby lowering water injection pressure caused by organic fouling,increasing the injection volume of injection wells,and ultimately improving oil recovery efficiency.展开更多
An environmentally friendly waterborne polyurethane(CWPU)emulsion was developed via a dual modification strategy by combining both the silane coupling agent KH-602 with renewable castor oil(CO)as a sustainable substit...An environmentally friendly waterborne polyurethane(CWPU)emulsion was developed via a dual modification strategy by combining both the silane coupling agent KH-602 with renewable castor oil(CO)as a sustainable substitute for petroleum-based polyols.The resulting materials were thoroughly characterized using Fourier-transform infrared spectroscopy(FTIR),thermogravimetric analysis(TGA),and differential scanning calorimetry(DSC).Furthermore,the influence of KH-602 content on the material properties was systematically investigated.The experimental results reveal that the incorporation of KH-602 significantly improves the thermal stability of the composite coating.As the KH-602 content increases,the tensile strength exhibits a gradual enhancement,while the elongation at break displays an initial increase followed by a subsequent decline.At an optimal KH-602 content of 3%,the coating demonstrates a balanced performance,achieving a tensile strength of 14.19 MPa and an elongation at break of 731.12%.These results suggest that the dual modification approach enhances mechanical and thermal properties while maintaining water resistance,making it suitable for sustainable coating applications.展开更多
基金financially supported by the National Natural Science Foundation of China(No.21404112)Ningbo Key Scientific and Technological Project(No.2014B10023)+2 种基金Ningbo Natural Science Foundation(No.2015A610016)Open Project of Key Laboratory of Marine Materials and Related Technologies(No.2016K07)Ningbo Science and Technology Innovation Team(No.2015B11003)
文摘In this work, a series of high performance bio-based polyurethanes（bio-PUs） were synthesized from polylactide（PLA）-based diols, different diisocyanates（TDI, MDI, HDI, IPDI） and chain extender 1,4-butanediol, in which different soft and hard segments are used to adjust their transition temperatures and mechanical properties. Poly（lactide-co-caprolactone）copolymer diols（co-PLAols） instead of PLA diols as the soft segment improved the thermal stability and mechanical properties of the synthesized bio-PUs. Among them, MDI-based bio-PUs have the highest T_g（43.8 °C）, tensile strength（23.5 MPa） and modulus（380.8 MPa）, while HDI-based bio-PUs have the lowest T_g（21.4 °C） and highest elongation at break（580%）. Especially, the bio-PUs synthesized from co-PLAols and MDI demonstrate better mechanical properties,closed to petroleum-based commodities. Furthermore, the obtained bio-PUs display good shape memory properties at body temperature and cytocompatibility. Therefore, these bio-PUs are promising for applications in biomedical fields.
基金National Key R&D Program of China(No.2021YFE0105100)Fok Ying-Tung Education Foundation,China(No.171065)Shanghai Rising-Star Program,China(No.20QA1400500)。
文摘Elastic bio-based waterproof and breathable membranes(EBWBMs) allow the passage of water vapor effectively and resist the penetration of liquid water,making it ideal for use under extreme conditions.In this study,we used a facile strategy to design the bio-based polyurethane(PU) nanofibrous membranes with the nanoscale porous structure to provide the membranes with high waterproof and breathable performances.The optimization of nanofibrous membrane formation was accomplished by controlling the relative ambient humidity to modulate the cooperating effects of charge dissipation and non-solvent-induced phase separation.The obtained EBWBMs showed multiple functional properties,with a hydrostatic pressure of 86.41 kPa and a water vapor transmission(WVT) rate of 10.1 kg·m^(-2)·d^(-1).After 1 000 cycles of stretching at 40% strain,the EBWBMs retained over 59% of the original maximum stress and exhibited an ideal elasticity recovery ratio of 85%.Besides,even after 80% deformation,the EBWBMs still maintained a hydrostatic pressure of 30.65 kPa and a WVT rate of 13.6 kg·m^(-2)·d^(-1),suggesting that bio-based PU nanofibrous membranes could be used for protection under extreme conditions.
文摘Through systematical experiment design, the physical blowing agent(PBA) mass loss of bio-based polyurethane rigid foam(PURF)in the foaming process was measured and calculated in this study, and different eco-friendly PBA mass losses were measured quantitatively for the first time. The core of the proposed method is to add water to replace the difference, and this method has a high fault tolerance rate for different foaming forms of foams. The method was proved to be stable and reliable through the standard deviations σ1and σ2for R1(ratio of the PBA mass loss to the material total mass except the PBA) and R2(ratio of the PBA mass loss to the PBA mass in the material total mass) in parallel experiments. It can be used to measure and calculate the actual PBA mass loss in the foaming process of both bio-based and petroleumbased PURF. The results show that the PBA mass loss in PURF with different PBA systems is controlled by its initial mass content of PBA in PU materials ω. The main way for PBA to dissipate into the air is evaporation/escape along the upper surface of foam. This study further reveals the mechanism of PBA mass loss: the evaporation/escape of PBA along the upper surface of foam is a typical diffusion behavior. Its spread power comes from the difference between the chemical potential of PBA in the interface layer and that in the outside air. For a certain PURF system, R1has approximately linear relationship with the initial mass content of PBA in PU materials ω, which can be expressed by the functional relationship R1= kω, where k is a variable related to PBA’s own attributes.
基金supported by the National Natural Science Foundation of China(Nos.52273119,51973018 and 81571410)the Beijing Science and Technology Project(Z191100002019017).
文摘Irregular articular cartilage injury is a common type of joint trauma,often resulting from intense impacts and other factors that lead to irregularly shaped wounds,the limited regenerative capacity of cartilage and the mismatched shape of the scaffods have contributed to unsatisfactory therapeutic outcomes.While injectable materials are a traditional solution to adapt to irregular cartilage defects,they have limitations,and injectable materials often lack the porous microstructures favorable for the rapid proliferation of cartilage cells.In this study,an injectable porous polyurethane scaffold named PU-BDO-Gelatin-Foam(PUBGF)was prepared.After injection into cartilage defects,PUBGF forms in situ at the site of the defect and exhibits a dynamic microstructure during the initial two weeks.This dynamic microstructure endows the scaffold with the ability to retain substances within its interior,thereby enhancing its capacity to promote chondrogenesis.Furthermore,the chondral repair efficacy of PUBGF was validated by directly injecting it into rat articular cartilage injury sites.The injectable PUBGF scaffold demonstrates a superior potential for promoting the repair of cartilage defects when compared to traditional porous polyurethane scaffolds.The substance retention ability of this injectable porous scaffold makes it a promising option for clinical applications.
基金supported by the Commercialization Promotion Agency for R&D Outcomes(COMPA)grant funded by the Korean Government(Ministery of Science and ICT),(No.RS-2023–00304743).
文摘To alleviate the pressure on the petrochemical industry and address environmental concerns,the utilization of polyurethane(PU)derived from castor oil(CO)(as an ester polyol replacement of petrochemicalbased materials)has garnered significant attention in recent decades.Extending the service life of materials requires imparting self-healing properties to vegetable oil-based polymers,an aspect that has received limited attention in current studies.However,low self-healing efficiency still poses a significant challenge,and non-conductivity also remains an obstacle in current research,crucial for their application in electronic devices.In this work,we present the first series of electrically self-healing biopolymer composites constructed by incorporating carbon nanotube(CNT)networks into crosslinked castor oil-based polyurethane(BPU)through a simple curing process.These materials address the challenges mentioned above and exhibit improved mechanical,electrical,and self-healing capabilities compared to other biobased self-healing materials.The resulting BPU/CNT composite demonstrated exceptional repeated selfhealing capacity,restoring both mechanical properties and electrical performance even after experiencing severe mechanical damage.Notably,this composite served as a conductive substrate in flexible solid-state supercapacitor(FSSC)devices.Consequently,the FSSC derived from the composite conductive substrate achieved an impressive 92.4%self-healing efficiency even after undergoing 7 cutting/healing cycles.The device remained virtually unchanged even after being bent at a 180°angle with a bending radius of 1.6 mm,indicating excellent repeatability and durability.The exceptional self-healing ability,with∼98%electrical recovery at 100℃for 70 s and 93%at 80℃after 6 min,of these composites was attributed to the synergistic interactions of the dynamic exchange reactions of disulfide bonds and dense hydrogen bonds within the BPU matrix,which provide a reversible dynamic polymer network.The healing efficiency of these dynamic bonds was evaluated by adjusting the composition ratio of the long linear chain of pTHF in hybrid polyols of the crosslinked polymer network.Overall,this work highlights a series of green,simple,and highly efficient self-healing polymer composites derived from renewable castor oil,and it establishes an essential framework for future sustainable polymer composite design.
文摘The Publisher regrets that the Graphical Abstract(see below)was missed due to a transmittal problem,and it was not published with the original article.
基金funded by projects“Smart Materials,Photonics,Technologies and Engineering Ecosystem(MOTE)”(Contract No.VPP-EM-FOTONIKA-2022/1-0001)“Bio-Based Cryogenic Insulation for Aerospace Application(BioSpace)”(Contract No.4000135271/21/NL/SC).
文摘Cryogenic insulation material rigid polyurethane(PU)foams were developed using bio-based and recycled feedstock.Polyols obtained from tall oil fatty acids produced as a side stream of wood biomass pulping and recycled polyethylene terephthalate were used to develop rigid PU foam formulations.The 4th generation physical blowing agents with low global warming potential and low ozone depletion potential were used to develop rigid PU foam cryogenic insulation with excellent mechanical and thermal properties.Obtained rigid PU foams had a thermal conductivity coefficient as low as 0.0171 W/m·K and an apparent density of 37-40 kg/m^(3).The developed rigid PU foams had anisotropic compression strength properties,which were higher parallel to the foaming direction.Moreover,the compression strength was also influenced by the type of applied bio-based polyol.The bio-based polyols with higher OH group functionality delivered higher crosslinking density of polymer matrix;thus,the mechanical properties were also higher.The mechanical strength of the foams increased when materials were tested at liquid nitrogen temperature due to the stiffening of the polymer matrix.The thermal properties of the developed materials were determined using differential scanning calorimetry,dynamic mechanical analysis,and thermogravimetric analysis methods.Lastly,the developed rigid PU foams had good adhesion to the aluminium substrate before and after applying cyroshock and an excellent safety coefficient of 4-5.Rigid PU foams developed using Solstice LBA delivered adhesion strength of~0.5 MPa and may be considered for application as cryogenic insulation in the aerospace industry.
基金supported by the China Postdoctoral Science Foundation(No.200902090)Tianjin Enterprise Science and Technology Commissioner Project(No.21YDTPJC00570).
文摘PU,or polyurethane,features a repeating urethane group(-NH-COO-)in its molecular structure.Traditionally,PUs are synthesized from isocyanate and polyol compounds derived from fossil resources through polymerization reactions.The depletion of fossil fuels and the increasing climate problems call for the expansion of more renewable sources of chemicals,such as modern biomass.However,the conversion of biomass into chemicals is challenging due to the inherent molecular complexity of its composition.In recent years,advances in green chemistry have led researchers to focus on developing bio-based polyurethanes by sourcing polyols,isocyanates,and chain extender precursors from biological materials.This paper focuses on the preparation of polyols,non-isocyanates and bio-based chain extenders from bio-based materials such as vegetable oils,lignin,sugars,and rosin.The synthetic routes and properties of several bio-based polyurethane materials are analyzed.Additionally,it discusses the current status,future challenges,and potential applications of bio-based polyurethane materials across various fields.
基金Funded by the National Natural Science Foundation of China(No.52370128)the Fundamental Research Funds for the Central Universities(No.2572022AW54)。
文摘This study identified castor oil and phosphate ester as effective retarders through setting time,tensile,and flexural tests,and determined their optimal dosages.The mechanism by which phosphate ester affects the setting time of polyurethane was further investigated using molecular dynamics simulations.Fourier transform infrared spectroscopy was also employed to systematically study the physical and chemical interactions between phosphate esters and polyurethane materials.The results demonstrate that a 1%concentration of phosphate ester provides the most effective retarding effect with minimal impact on the strength of polyurethane.When phosphate ester is added to the B component of the two-component polyurethane system,its interaction energy with component A decreases,as do the diffusion coefficient and aggregation degree of component B on the surface of component A.This reduction in interaction slows the setting time.Additionally,the addition of phosphate ester to polyurethane leads to the disappearance or weakening of functional groups,indicating competitive interactions within the phosphate ester components that inhibit the reaction rate.
基金the financial support from the Fujian Science Foundation for Outstanding Youth(2023J06039)the National Natural Science Foundation of China(Grant No.41977259,U2005205,41972268)the Independent Research Project of Technology Innovation Center for Monitoring and Restoration Engineering of Ecological Fragile Zone in Southeast China(KY-090000-04-2022-019)。
文摘Shotcrete is one of the common solutions for shallow sliding.It works by forming a protective layer with high strength and cementing the loose soil particles on the slope surface to prevent shallow sliding.However,the solidification time of conventional cement paste is long when shotcrete is used to treat cohesionless soil landslide.The idea of reinforcing slope with polyurethane solidified soil(i.e.,mixture of polyurethane and sand)was proposed.Model tests and finite element analysis were carried out to study the effectiveness of the proposed new method on the emergency treatment of cohesionless soil landslide.Surcharge loading on the crest of the slope was applied step by step until landslide was triggered so as to test and compare the stability and bearing capacity of slope models with different conditions.The simulated slope displacements were relatively close to the measured results,and the simulated slope deformation characteristics were in good agreement with the observed phenomena,which verifies the accuracy of the numerical method.Under the condition of surcharge loading on the crest of the slope,the unreinforced slope slid when the surcharge loading exceeded 30 k Pa,which presented a failure mode of local instability and collapse at the shallow layer of slope top.The reinforced slope remained stable even when the surcharge loading reached 48 k Pa.The displacement of the reinforced slope was reduced by more than 95%.Overall,this study verifies the effectiveness of polyurethane in the emergency treatment of cohesionless soil landslide and should have broad application prospects in the field of geological disasters concerning the safety of people's live.
文摘Doping perylene diimide(PDI)into a polymer matrix is a simple strategy to prepare near-infrared(NIR)reflective materials,but the mechanical properties and NIR reflectance properties are significantly compromised due to macro-phase separation.In this study,a novel polymer(denoted as PU-PDI)with intrinsic NIR reflective proper⁃ties was synthesized by covalent incorporation of PDI units into polyurethane chains.Its photophysical characteris⁃tics,mechanical property and NIR reflectance property are investigated in detail.The results show that covalent in⁃corporation reduces the severe aggregation of PDI units,thereby endows PU-PDI with excellent mechanical property.The elongation at break of PU-PDI can reach more than 700%,and the breaking strength is 34.11 MPa.Moreover,compared to the blending system,PU-PDI possesses enhanced NIR reflection ability due to the better dispersion of PDI units.
基金supported by the National Natural Science Foundation of China(Nos.42207353 and 42277408)the Key Research and Development Program of Jiangsu Province of China(BE2021378)+1 种基金Jiangsu Agricultural Science and Technology Independent Innovation Fund of China(CX(21)-1009)the Earmarked Fund of China Agriculture Research System(CARS-10-Sweetpotato)。
文摘Dear Editor,Environmental pollution from microplastics(MPs)has recently gained attention as a potential environmental hazard(Chia et al.,2021).Agricultural soils could contain more MPs than the ocean by 2050 because more MPs enter the soil than the ocean(Nizzetto et al.,2016).The carbon(C)-C backbone of degradation-resistant MPs provides considerable stability in the soil,where they can remain for several decades(Iqbal et al.,2023).
基金financially supported by Applied Basic Research Project of Qinghai province(2023-ZJ-774)。
文摘Boron adsorbents with high adsorption capacities have long been a focus of research for a long time.This study used small molecular polyols with different hydroxyl groups as functional monomers and as end-capping agents,functional dendritic polyurethanes with nano structure were successfully prepared by one-pot method.The single molecule size and surface morphology were characterized by dynamic light scattering,transmission electron microscopy and scanning electron microscopy,and the molecular size in the dry state was 11 to 18 nm.The prepared materials were used as the boron adsorbents,and the effects of pH,time,boron solution concentration and temperature on the adsorption were studied.The results showed that the capacity of adsorbed boron could reach 110-130 mg·g^(-1).Adsorption was a homogeneous monolayer adsorption controlled by chemisorption,and adsorption thermodynamics showed that was a spontaneous endothermic process.Adsorption behavior was best described by the pseudo-second-order kinetic model and the Langmuir isotherm.This study also showed that it was difficult for ortho/meta-hydroxyl groups to chelate with H_(3)BO_(3) and other polyborates,and the chelates mainly had good chelating properties with B(OH)_(4)^(-),and the chelates formed had large steric hindrance.At the same time,increasing the number of hydroxyl groups of functional monomers was beneficial to increase the adsorption capacity of materials.In addition,the cyclic adsorption/desorption experiments showed that DPUs have good cyclic stability.At the same time,the adsorption results of the original salt lake brine showed that other metal ions in the brine had little effect on the adsorption of boron,and the adsorption capacity was as high as52.93 mg·g^(-1),and the maximum adsorption capacity was obtained by Adams-Bohart model to58.80 mg·g^(-1).The outstanding selectivity and adsorption capacity of these materials have broad potential application,and are expected to be used for the efficient adsorption and removal in boroncontaining water bodies.
基金supported by the China Postdoctoral Science Foundation(No.2023M743622)Natural Science Foundation of Ningbo City(No.2024J109)+2 种基金National Natural Science Foundation of China(Nos.E52307038 and U23A20589)Ningbo 2025 Key Scientific Research Programs(Nos.2022Z111,2022Z160 and 2022Z198)the Leading Innovativeand Entrepreneur Team Introduction Program of Zhejiang(No.2021R01005).
文摘The demand for energy-efficient and environmental-friendly power grid construction has made the exploitation of bio-based electrical epoxy resins with excellent properties increasingly important.This work developed the bio-based electrotechnical epoxy resins based on magnolol.High-performance epoxy resin(DGEMT)with a double crosslinked points and its composites(Al_(2)O_(3)/DGEMT)were obtained taking advantages of the two bifunctional groups(allyl and phenolic hydroxyl groups)of magnolol.Benefitting from the distinctive structure of DGEMT,the Al_(2)O_(3)/DGEMT composites exhibited the advantages of intrinsically high thermal conductivity,high insulation,and low dielectric loss.The AC breakdown strength and thermal conductivity of Al_(2)O_(3)/DGEMT composites were 35.5 kV/mm and 1.19 W·m-1·K-1,respectively,which were 15.6%and 52.6%higher than those of petroleum-based composites(Al_(2)O_(3)/DGEBA).And its dielectric loss tanδ=0.0046 was 20.7%lower than that of Al_(2)O_(3)/DGEBA.Furthermore,the mechanical,thermal and processing properties of Al_(2)O_(3)/DGEMT are fully comparable to those of Al_(2)O_(3)/DGEBA.This work confirms the feasibility of manufacturing environmentally friendly power equipment using bio-based epoxy resins,which has excellent engineering applications.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(RS-2024-00451587)supported by Post-plastic Specialized Graduate Program through the Korea Environmental Industry&Technology Institute(KEITI)funded by the Ministry of Environment(MOE).
文摘Bio-polyol is considered as a core material to synthesize eco-friendly polyurethane products.However,one of the popular bio-polyols,polytrimethylene ether glycol(PO3G),is reluctant to crystallize and therefore exhibits a cold crystallization behavior.This abnormal behavior causes unstable mechanical properties at low-temperature and limits its applications in shape memory devices where crystallization is an essential mechanism.To analyze the unusual phenomenon,we compared different ether polyols focusing on symmetry characteristics and the evenodd effect of carbon backbones.It is found that PO3G has a slow crystallization rate because its ether linkages require specific chain arrangement for attractive interactions.Consequently,a thermal learning mechanism is developed to restore the normal crystallization behavior of elastomers synthesized from the bio-polyol.Repetitive heating and cooling cycles with high-temperature annealing induce urethane exchange reaction and reconstruct the chain orientations for fast crystallization.Results suggest the degree of crystallizations in polyurethane elastomer can be precisely controlled by introducing repetitive thermal treatments to enhance the potential applications of bio-polyols in polymer industries.
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supported by Shiraz University of Medical Sciences,Shiraz,Iran(grant No.:17780).
文摘Due to the limited regeneration capacity of myocardial tissue after infarction,designing tissue engineering scaffolds are in demand.In the present study,electrospun nanofibrous scaffolds were made out of polyurethane,collagen and gold nanoparticles with random and aligned nanofiber morphologies.The nanoparticles were green-synthesized using saffron extract.Nanoparticle characterizations with UV-Vis.spectroscopy and DLS illustrated theoretical and hydrodynamic diameters of around 7 and 13 nm,respectively,having zeta potential of−37 mV.SEM and TEM micrographs showed the morphology and diameters of obtained nanofibers.Also,further characterization were done by ATR-FTIR,XRD and TGA investigations and degradation studies.Contact angle measurements showed hydrophilic nature of the scaffolds(59±0.6°for aligned PU/Col/Au50 nanofibers compared to 120±2.6°for random PU nanofibers).Mechanical testing demonstrated appropriate tensile properties of the scaffolds for cardiac tissue engineering(Young’s modulus:1.53±0.07 MPa for aligned PU/Col/Au50 nanofibers compared to 0.4±0.05 MPa for random PU nanofibers).Finally,alamar blue assay revealed proper survival of the cells of HUVEC cell line on the prepared scaffolds,where the highest percentages were observed for random and aligned PU/Col/Au50 nanofibers.According to the findings,the fabricated PU/Col/AuNPs nanofibrous scaffolds could be considered as potential cardiac patches.
基金financially supported by the National Key R&D Program of China(No.2022YFC2805103)the National Natural Science Foundation of China(Nos.52022031 and 52263001)the Foundation from Qinghai Science and Technology Department(No.2022-ZJ-944Q)。
文摘Incorporation of acetal groups in the backbone is a potent strategy to create polymers that are cleavable or degradable under acidic conditions.We report here an in-depth study on the ring-closing-opening copolymerization of o-phthalaldehyde(OPA)and epoxide using Lewis pair type two-component organocatalysts for producing acetal-functionalized polyether and polyurethane.Notably,triethylborane as the Lewis acid,in comparison with tri(n-butyl)borane,more effectively enhances the polymerization activity by mitigating borane-induced reduction of the aldehyde group into extra initiating(borinic ester)species.Density functional theory(DFT)calculations present comparable energy barriers of OPA-epoxide cross-propagation and epoxide self-propagation,which is consistent with the experimental finding that an alternating-rich copolymer comprising mostly OPA-epoxide units but also epoxide-epoxide linkages is produced.In particular,when epoxide is added in a large excess,the product becomes a polyether containing acetal functionalities in the central part of the backbone and thus being convertible into polyurethane with refined acid degradability.
文摘By investigating the performance characteristics of the bio-based surfactant 8901A,a composite decontamination and injection system was developed using 8901A as the primary agent,tailored for application in low-permeability and heavy oil reservoirs under varying temperature conditions.The results demonstrate that this system effectively reduces oil–water interfacial tension,achieving an ultra-low interfacial tension state.The static oil washing efficiency of oil sands exceeds 85%,the average pressure reduction rate reaches 21.55%,and the oil recovery rate improves by 13.54%.These enhancements significantly increase the system’s ability to dissolve oilbased blockages,thereby lowering water injection pressure caused by organic fouling,increasing the injection volume of injection wells,and ultimately improving oil recovery efficiency.
基金Funded by the Basic Scientific Research of Liaoning Provincial Department of Education(No.LJ212410153030)。
文摘An environmentally friendly waterborne polyurethane(CWPU)emulsion was developed via a dual modification strategy by combining both the silane coupling agent KH-602 with renewable castor oil(CO)as a sustainable substitute for petroleum-based polyols.The resulting materials were thoroughly characterized using Fourier-transform infrared spectroscopy(FTIR),thermogravimetric analysis(TGA),and differential scanning calorimetry(DSC).Furthermore,the influence of KH-602 content on the material properties was systematically investigated.The experimental results reveal that the incorporation of KH-602 significantly improves the thermal stability of the composite coating.As the KH-602 content increases,the tensile strength exhibits a gradual enhancement,while the elongation at break displays an initial increase followed by a subsequent decline.At an optimal KH-602 content of 3%,the coating demonstrates a balanced performance,achieving a tensile strength of 14.19 MPa and an elongation at break of 731.12%.These results suggest that the dual modification approach enhances mechanical and thermal properties while maintaining water resistance,making it suitable for sustainable coating applications.
