Bio-based polyurethane foam has attracted increasing attentions due to eco-friendliness and fossil feedstock issues.However,the inherent flammability limits its application in different fields.Herein,we demonstrate a ...Bio-based polyurethane foam has attracted increasing attentions due to eco-friendliness and fossil feedstock issues.However,the inherent flammability limits its application in different fields.Herein,we demonstrate a green bio-based flame-retardant system to fabricate polyurethane foam composite with durable flame retardancy,smoke suppression,and thermal insulation property.In this system,the green bio-based polyol(VED)with good reactivity and compatibility plays a role of flame retardant and EG acts as a synergistic filler.As a result,the LOI value of foam composite increased to 30.5 vol.%and it achieved a V-0 rating in the UL-94 vertical burning test.Additionally,the peak heat release rate(pHRR)and the total smoke production(TSP)decreased by 66.1%and 63.4%,respectively.Furthermore,the foam composite maintained durable flame retardancy after accelerated thermal aging test,whose thermal-insulating property was maintained even after being treated in high-humidity environment with 85%R.H.for a week.This work provides a facile strategy for durable flame retardancy and long-term thermal insulation performance,and creates opportunities for the practical applications of bio-based foam composites.展开更多
Biomass phytic acid has potential flame retardant value as the main form of phosphorus in plant seeds.In this study,phytate-based flame retardants aluminum phytate(PA-Al)and iron phytate(PA-Fe)were synthesized and cha...Biomass phytic acid has potential flame retardant value as the main form of phosphorus in plant seeds.In this study,phytate-based flame retardants aluminum phytate(PA-Al)and iron phytate(PA-Fe)were synthesized and characterized.Subsequently,they were introduced into rigid polyurethane foam(RPUF)as flame retardants by one-step water-blown method.The results indicated that RPUF/PA-Fe30 exhibited the highest char residue of 22.1 wt%,significantly higher than 12.4 wt%of RPUF.Cone calorimetry analysis showed that the total heat release(THR)of RPUF/PA-Al30 decreased by 17.0%and total smoke release(TSR)decreased by 22.0%compared with pure RPUF,which were the lowest,demonstrating a low fire risk and good smoke suppression.Thermogravimetric analysis-Fourier transform infrared spectrometer(TG-FTIR)implied the release intensity of flammable gases(hydrocarbons,esters)and toxic gases(isocyanate,CO,aromatic compounds,HCN)of composites was significantly reduced after the addition of PA-Fe.The analysis of char residue indicated that the RPUF composites formed a dense char layer with a high degree of graphitization after the addition of PA-Al/PA-Fe,endowing RPUF composites with excellent mass&heat transmission inhibition effect and fire resistance in the combustion process.展开更多
With the escalating global emphasis on environmental conservation and sustainable development,enhancing the service quality and durability of road surfaces and facilitating the green development of highways have comma...With the escalating global emphasis on environmental conservation and sustainable development,enhancing the service quality and durability of road surfaces and facilitating the green development of highways have commanded considerable attention.Bio-based polyurethane,on account of its remarkable physical and chemical properties,green,sustainable and renewable capacity,as well as its structural design capabilities,has drawn widespread attention and numerous studies have been carried out.It has gradually started to substitute traditional petroleum-based polyurethane materials in road engineering.Nevertheless,the application of bio-based polyurethane materials in road engineering remains in the exploratory phase.To stimulate the application research of bio-based polyurethane materials in road engineering and offer additional research directions,this paper reviews the research advancements of bio-based polyurethane materials and their applications in road engineering.The fundamental classification of bio-based polyurethane is introduced.The characteristics and challenges associated with various preparation methods for bio-based polyurethane are described.The influence of bio-based polyurethane on road engineering materials are analyzed.The evaluation indicators of bio-based polyurethane within the life cycle of road engineering are investigated.Finally,the development tendency towards in road engineering applications are forecasted.This paper provides a reference for the study of bio-based polyurethane materials in road engineering applications.展开更多
Environment friendly and intelligent surfactants have attracted great attention in recent years.A bio-based CO_(2)responsive surfactant rosin acid dimaleimide choline(R-BMI-C)with an extremely rigid skeleton was prepa...Environment friendly and intelligent surfactants have attracted great attention in recent years.A bio-based CO_(2)responsive surfactant rosin acid dimaleimide choline(R-BMI-C)with an extremely rigid skeleton was prepared using rosin and choline as raw materials by Diels-Alder addition reaction and acid-base neutralization reactions.Its structure was confirmed by IR and^(1)H NMR spectra.The foams’properties of R-BMI-C could be adjusted by bubbling CO_(2)/N_(2)to change the structure of the surfactant.At pH 10.4,R-BMI-C forms an unstable foam with a half-life of 1.5 h.When the pH was reduced to 7.4 by bubbling CO_(2),R-BMI-C forms an extremely stable foam with a half-life of 336 h.The surfactant R-BMI-C changed from bola type to conventional type when bubbling CO_(2).And the internal aggregation structure of R-BMI-C aqueous solution changed from spherical micelles to laminar micelles according to the cryogenic-transmission electron microscope.We know that the lamellar structure tends to adsorb at the air/water interface or is trapped in the foam film,which slows down the foam coarsening and agglomeration process,resulting in a significant increase in foam stability.R-BMI-C could be used in oil extraction,fire-fighting and chemical decontamination due to its excellent foaming,stabilization and defoaming properties.展开更多
The current global shortage of oil resources and the pollution problems caused by traditional barrier materials urgently require the search for new substitutes.Biodegradable bio-based barrier materials possess the cha...The current global shortage of oil resources and the pollution problems caused by traditional barrier materials urgently require the search for new substitutes.Biodegradable bio-based barrier materials possess the characteristics of being renewable,environmentally friendly,and having excellent barrier properties.They have become an important choice in fields such as food packaging,agricultural film covering,and medical protection.This review systematically analyzes the design and research of this type of material,classifying biobased and biodegradable barrier materials based on the sources of raw materials and synthesis pathways.It also provides a detailed introduction to the latest research progress of biobased and biodegradable barrier materials,discussing the synthesis methods and improvement measures of their barrier properties.Subsequently,it analyzes the related technologies for enhancing the barrier properties of biobased and biodegradable barrier materials,and finally looks forward to the directions that future research should focus on,promoting the transition of biobased and biodegradable barrier materials from the laboratory to industrial applications.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
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
Aging plays a critical role in determining the durability and long-term performance of asphalt pavements,as it is influenced by both external factors(e.g.,temperature,ultraviolet(UV)radiation,moisture,oxidative gases)...Aging plays a critical role in determining the durability and long-term performance of asphalt pavements,as it is influenced by both external factors(e.g.,temperature,ultraviolet(UV)radiation,moisture,oxidative gases)and internal factors such as binder composition.Although laboratory simulations of aging are well established for conventional bituminous binders,limited attention has been paid to replicating and evaluating aging processes in bio-based binders.This review provides a comprehensive analysis of current laboratory techniques for simulating and assessing binder aging,with a focus on two key areas:aging simulation protocols and evaluation methodologies.The analysis shows that although several efforts have been made to incorporate external aging factors into lab simulations,significant challenges persist,especially in the case of bio-based binders,which are characterized by a high variability in composition and limited understanding of their aging behavior.Current evaluation approaches also exhibit limitations.Improvements are needed in the molecular-level analysis of oxidation(e.g.,through more representative oxidation modelsin molecular dynamicssimulations),in the separation and quantification of binder constituents,and in the application of advanced techniques such as fluorescence microscopy to better characterize polymer dispersion.To enhance the reliability of laboratory simulations,future research should aim to improve the correlation between laboratory and field aging,define robust aging indexes,and refine characterization methods.These advancements are particularly critical for bio-based binders,whose performance is highly sensitive to aging and for which standard test protocols are still underdeveloped.A deeper understanding of aging mechanisms in both polymer-modified and biobased binders,along with improved analytical tools for assessing oxidative degradation and morphological changes,will be essential to support the development of sustainable,high-performance paving materials.展开更多
In the context of transitioning toward more sustainable construction materials,this study explores the impact of incorporating millet husks as an alternative to sand on the physical,mechanical,and thermal performance ...In the context of transitioning toward more sustainable construction materials,this study explores the impact of incorporating millet husks as an alternative to sand on the physical,mechanical,and thermal performance of lightweight concrete.Through a mixture design approach,five formulations were selected and thoroughly characterized.The analysis of iso-response curves enabled an in-depth assessment of the cross-effects between formulation parameters and their interactions on the final properties of the material.The results show that integrating millet husks leads to a significant reduction in density,reaching up to 21%,while maintaining notable mechanical performance.A balanced formulation of sand and fibers achieved a maximum compressive strength of 12.11 MPa,demonstrating that,under specific conditions,plant fibers actively contribute to the structural integrity of the composite.In tensile strength,the positive influence of fibers is even more pronounced,with a maximum resistance of 8.62 MPa,highlighting their role in enhancing material cohesion.From a thermal perspective,millet husks reduce both thermal conductivity and effusivity,thereby limiting heat transfer and accumulation within the composite.Iso-response curve analysis reveals that these effects are directly linked to the proportions of the constituents and that achieving an optimal balance between sand,fibers,and cement is key to maximizing performance.These findings demonstrate that the adopted approach allows moving beyond conventional substitution methods by identifying optimal configurations for the design of lightweight bio-based concretes that are both strong and insulating,thereby confirming the potential of millet husks in developing lightweight concretes suitable for sustainable construction applications.展开更多
An efficient and novel approach is proposed for oxidative arylation of bio-based furfuryl alcohol(FA)to aryl furans(AFs),a versatile monomer of photoelectric materials,in the presence of UiO-67-Pd(F)with phenanthrolin...An efficient and novel approach is proposed for oxidative arylation of bio-based furfuryl alcohol(FA)to aryl furans(AFs),a versatile monomer of photoelectric materials,in the presence of UiO-67-Pd(F)with phenanthroline/bipyridine,and poly-F substituted phenyl ligands as the mixture linkers.The results of control experiments and theoretical calculations reveal that the–F on the phenyl linkers efficiently tunes the electron-deficient nature of Pd through the Zr_(6) clusters bridges,which favors the adsorption and activation of the furan ring.Furthermore,the conjugation of different nitrogen-containing ligands facilitates Pd coordination for the Heck-type insertion and subsequent electrophilic palladation,respectively.As a result,the oxidative arylation of FA derivatives is substantially enhanced because of these electronic and steric synergistic effects.Under the optimized conditions,72.2%FA conversion and 74.8%mono aryl furan(MAF)selectivity are shown in the Heck-type insertion.Meanwhile,85.3%of MAF is converted,affording 74.8%selectivity of final product(AFs)in the subsequent electrophilic palladation reaction.This process efficiency is remarkably higher than that with homogeneous catalysts.In addition,furan-benzene polymer obtained from the halogen-free synthesis catalyzed by UiO-67-Pd(F)show significantly better properties than that from conventional Suzuki coupling method.Therefore,the present work provides a new insight for useful AFs synthesis by oxidative arylation of bio-furan via rational tunning the metal center micro-environment of heterogeneous catalyst.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
The development of materials with excellent microwave absorption(MWA)and electromagnetic interference(EMI)shielding performances has currently received attention.Herein,mesophase pitch-based carbon foam(MPCF)with 3D i...The development of materials with excellent microwave absorption(MWA)and electromagnetic interference(EMI)shielding performances has currently received attention.Herein,mesophase pitch-based carbon foam(MPCF)with 3D interconnected pore structure was prepared through the high pressure pyrolysis of mesophase coal tar pitch.It is found that the 3D interconnected cellular pores of MPCF facilitate multiple reflections of electromagnetic waves,which results in the minimum reflection loss(RLmin)value of MPCF reaches-37.84 dB with the effective absorption bandwidth(EAB)of 5.44 GHz at a thickness of 2.70 mm,and the total average electromagnetic shielding effectiveness(SE_(T))under 3.00 mm thickness achieves 26.52 dB in X-band.Subsequently,MPCF is activated by KOH to obtain activated carbon foam(A-MPCF).The average SE_(T)of A-MPCF achieves 103.00 dB for abundant nanopores on the pore cell walls,which leads to a transition from the multiple reflections of electromagnetic waves on the walls to diffuse reflection.Unfortunately,the reflection coefficient(R)of A-MPCF increases from 0.78 to 0.90.To reduce the R value,Fe_(3)O_(4)/A-MPCF was fabricated via the in situ growth of nano Fe_(3)O_(4)on A-MPCF.Consequently,the R value of Fe_(3)O_(4)/A-MPCF was reduced from 0.90 to 0.74,whereas the MWA performance was only slightly decreased.This work proposes a simple strategy for simultaneously adjusting MWA and EMI shielding performances of materials.展开更多
Biofoam products have attracted considerable attention lately because there is a growing demand for green/sustainable products.To this end,various biobased foams have either been developed or are currently in developm...Biofoam products have attracted considerable attention lately because there is a growing demand for green/sustainable products.To this end,various biobased foams have either been developed or are currently in development,e.g.,bio-based polyurethanes(PUs),polylactic acid(PLA),starch,and polyhydroxyalkanotates(PHAs).Indeed,significant progress has been made;however,chal-lenges still persist,for example,biobased foam products have poor processability,inferior com-patibility,thermal and strength properties.In this review,we focus on five biofoam products:namely bio-based PUs,PLA,starch,PHAs,and cellulose biofoam products,along with their prop-erties and performance,as well as their manufacturing processes.Further efforts are still needed to unlock the full potential of these bio-based products and meet the goal of complementing and gradually replacing some of their fossil-based counterparts.Finally,the challenges,as well as arising opportunities of future research directions are discussed.展开更多
Waste glass fibers were used as the main raw materials to prepare foamed glass-ceramics with 0-14 wt%H_(3)BO_(3)as a flux agent.The effects of H_(3)BO_(3)on the crystallization process,foaming behavior,and physical pr...Waste glass fibers were used as the main raw materials to prepare foamed glass-ceramics with 0-14 wt%H_(3)BO_(3)as a flux agent.The effects of H_(3)BO_(3)on the crystallization process,foaming behavior,and physical properties of CaO-MgO-Al_(2)O_(3)-SiO_(2)foamed glass-ceramics were investigated.The results showed that the main crystalline phase of the foamed glass-ceramics was anorthite with diopside as a minor crystalline phase,which exhibited a typical surface crystallization process.The addition of H_(3)BO_(3)modified the surface of glass powders and inhibited crystal precipitation obviously.The low melting point of H_(3)BO_(3)and the decrease of crystallinity jointly promoted the growth of pores,resulting in a reduction of bulk density and an increase in porosity.The compressive strength and thermal conductivity of the samples were linearly related to the bulk density.In particular,the sample added with 10 wt%H_(3)BO_(3)exhibited excellent properties,possessing a low coefficient of thermal conductivity 0.081 W/(m·K)and relatively high compressive strength 3.36 MPa.展开更多
Directional three-dimensional carbon-based foams are emerging as highly attractive candidates for promising electromagnetic wave absorbing materials(EWAMs)thanks to their unique architecture,but their construction usu...Directional three-dimensional carbon-based foams are emerging as highly attractive candidates for promising electromagnetic wave absorbing materials(EWAMs)thanks to their unique architecture,but their construction usually involves complex procedures and extremely depends on unidirectional freezing technique.Herein,we propose a groundbreaking approach that leverages the assemblies of salting-out protein induced by ammonium metatungstate(AM)as the precursor,and then acquire directional three-dimensional carbon-based foams through simple pyrolysis.The electrostatic interaction between AM and protein ensures well dispersion of WC_(1−x)nanoparticles on carbon frameworks.The content of WC_(1−x)nanoparticles can be rationally regulated by AM dosage,and it also affects the electromagnetic(EM)properties of final carbon-based foams.The optimized foam exhibits exceptional EM absorption performance,achieving a remarkable minimum reflection loss of−72.0 dB and an effective absorption bandwidth of 6.3 GHz when EM wave propagates parallel to the directional pores.Such performance benefits from the synergistic effects of macroporous architecture and compositional design.Although there is a directional dependence of EM absorption,radar stealth simulation demonstrates that these foams can still promise considerable reduction in radar cross section with the change of incident angle.Moreover,COMSOL simulation further identifies their good performance in preventing EM interference among different electronic components.展开更多
It is essential to design economic and efficient tougheners to prepare high-performance epoxy resin;however,this has remained a huge challenge.Herein,an eco-friendly,low-cost,and facile-fabricated bio-based hyperbranc...It is essential to design economic and efficient tougheners to prepare high-performance epoxy resin;however,this has remained a huge challenge.Herein,an eco-friendly,low-cost,and facile-fabricated bio-based hyperbranched toughener,carboxylic acid-functionalized tannic acid(CATA),was successfully prepared and applicated to the preparation of solvent-free epoxy resins.The mechanical performance,morphology,structural characterization,and thermal characterization of toughened epoxy resin system were studied.The toughened epoxy resin system with only 1.0wt%CATA reached the highest impact strength,111%higher than the neat epoxy resin system.Notably,the tensile strength and elongation at break of toughened epoxy resin systems increased moderately with increasing CATA loading.Nonphase-separated hybrids with significant toughening effect were obtained.Additionally,the thermal stabilities of toughened epoxy resin systems decreased with increasing CATA loading.This study provides an eco-friendly,cost-effective,and facile approach for the preparation of high-performance,solvent-free epoxy resins with potential for practical applications in sealing integrated circuits and electrical devices fields.展开更多
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
In this study, monoglycidyl silyl etherated eugenol(GSE) was synthesized as reactive epoxy diluent, and the chemical structure of GSE, intermediates, and products were characterized by Fourier transform infrared spect...In this study, monoglycidyl silyl etherated eugenol(GSE) was synthesized as reactive epoxy diluent, and the chemical structure of GSE, intermediates, and products were characterized by Fourier transform infrared spectroscopy(FTIR) and nuclear magnetic resonance(~1 H-NMR). GSE existed as a potential bio-based reactive diluent for petroleum-based epoxy resin. The curing kinetics of EP/HHPA/GSE system was studied by non-isothermal DSC method. The kinetics parameters were calculated by using the Kissinger model, Crane model, Ozawa model, and β-T(temperature-heating rate) extrapolation, respectively. In addition, the effects of GSE on the thermo-mechanical properties and thermal stability of EP/HHPA/GSE systems were studied, indicating that GSE can effectively improve the toughness and thermal decomposition temperature of the epoxy system.展开更多
Many natural fibers are lightweight and display remarkable strength and toughness.These properties originate from the fibers’hierarchical structures,assembled from the molecular to macroscopic scale.The natural spinn...Many natural fibers are lightweight and display remarkable strength and toughness.These properties originate from the fibers’hierarchical structures,assembled from the molecular to macroscopic scale.The natural spinning systems that produce such fibers are highly energy efficient,inspiring researchers to mimic these processes to realize robust artificial spinning.Significant developments have been achieved in recent years toward the preparation of high-performance bio-based fibers.Beyond excellent mechanical properties,bio-based fibers can be functionalized with a series of new features,thus expanding their sophisticated applications in smart textiles,electronic sensors,and biomedical engineering.Here,recent progress in the construction of bio-based fibers is outlined.Various bioinspired spinning methods,strengthening strategies for mechanically strong fibers,and the diverse applications of these fibers are discussed.Moreover,challenges in reproducing the mechanical performance of natural systems and understanding their dynamic spinning process are presented.Finally,a perspective on the development of biological fibers is given.展开更多
Polyvinyl alcohol (PVA) has been widely used in the fields of medical, food and packaging due to its excellentbiocompatibility, good fiber-forming and film-forming properties. However, the high flammability of PVA has...Polyvinyl alcohol (PVA) has been widely used in the fields of medical, food and packaging due to its excellentbiocompatibility, good fiber-forming and film-forming properties. However, the high flammability of PVA hasgreatly limited its wider applications. The flame-retardant PVA was prepared by melt blending of a bio-basedflame retardant (prepared from lignin, phosphoric acid and carbamide) with thermoplastic PVA (TPVA). Thechemical structure, morphology, thermal properties, mechanical properties, fire property and fluidity of thisflame retardant PVA were investigated by Fourier transform infrared spectrometer(FTIR), field emission scanning electron microscope(SEM), thermogravimetric analyzer(TGA), impact tester, universal testing machine,horizontal-vertical burning tester, limiting oxygen indexer(LOI) and melt flow rate meter(MFR). The resultsshowed that the prepared flame retardant had good compatibility with the PVA substrate;The impact strength,melt flow rate, fire property and char residue of this PVA material increased with the content of bio-based flameretardant. When the content of flame retardant was of 20%, the five indices including impact strength, meltflow rate, UL-94 level, LOI and char residual were 11.3 KJ/m^(2), 21.2 g/10 min, V-0 UL-94 level, 33.1%, and19.2%, respectively. This research can promote the high-value utilization of lignin and the application ofPVA in the fields of fire protection.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22175123,52122302,and 51991351)the 111 Project(No.B20001)Fundamental Research Funds for the Central Universities,and Open and Innovative Fund of Hubei Three Gorges Laboratory(Nos.2022LF2021 and SC213011).
文摘Bio-based polyurethane foam has attracted increasing attentions due to eco-friendliness and fossil feedstock issues.However,the inherent flammability limits its application in different fields.Herein,we demonstrate a green bio-based flame-retardant system to fabricate polyurethane foam composite with durable flame retardancy,smoke suppression,and thermal insulation property.In this system,the green bio-based polyol(VED)with good reactivity and compatibility plays a role of flame retardant and EG acts as a synergistic filler.As a result,the LOI value of foam composite increased to 30.5 vol.%and it achieved a V-0 rating in the UL-94 vertical burning test.Additionally,the peak heat release rate(pHRR)and the total smoke production(TSP)decreased by 66.1%and 63.4%,respectively.Furthermore,the foam composite maintained durable flame retardancy after accelerated thermal aging test,whose thermal-insulating property was maintained even after being treated in high-humidity environment with 85%R.H.for a week.This work provides a facile strategy for durable flame retardancy and long-term thermal insulation performance,and creates opportunities for the practical applications of bio-based foam composites.
基金This research was supported by National Key Research and Development Project(No.2017YFE0113200)National Natural Science Fund of China(Nos.51403004,U1833113).
文摘Biomass phytic acid has potential flame retardant value as the main form of phosphorus in plant seeds.In this study,phytate-based flame retardants aluminum phytate(PA-Al)and iron phytate(PA-Fe)were synthesized and characterized.Subsequently,they were introduced into rigid polyurethane foam(RPUF)as flame retardants by one-step water-blown method.The results indicated that RPUF/PA-Fe30 exhibited the highest char residue of 22.1 wt%,significantly higher than 12.4 wt%of RPUF.Cone calorimetry analysis showed that the total heat release(THR)of RPUF/PA-Al30 decreased by 17.0%and total smoke release(TSR)decreased by 22.0%compared with pure RPUF,which were the lowest,demonstrating a low fire risk and good smoke suppression.Thermogravimetric analysis-Fourier transform infrared spectrometer(TG-FTIR)implied the release intensity of flammable gases(hydrocarbons,esters)and toxic gases(isocyanate,CO,aromatic compounds,HCN)of composites was significantly reduced after the addition of PA-Fe.The analysis of char residue indicated that the RPUF composites formed a dense char layer with a high degree of graphitization after the addition of PA-Al/PA-Fe,endowing RPUF composites with excellent mass&heat transmission inhibition effect and fire resistance in the combustion process.
基金supported by the Key R&D Project in Shaanxi Province(No.2024GX-YBXM-371)Shaanxi Qinchuangyuan Scientists+Engineers Team Construction Project(2025QCY-KXJ-141).
文摘With the escalating global emphasis on environmental conservation and sustainable development,enhancing the service quality and durability of road surfaces and facilitating the green development of highways have commanded considerable attention.Bio-based polyurethane,on account of its remarkable physical and chemical properties,green,sustainable and renewable capacity,as well as its structural design capabilities,has drawn widespread attention and numerous studies have been carried out.It has gradually started to substitute traditional petroleum-based polyurethane materials in road engineering.Nevertheless,the application of bio-based polyurethane materials in road engineering remains in the exploratory phase.To stimulate the application research of bio-based polyurethane materials in road engineering and offer additional research directions,this paper reviews the research advancements of bio-based polyurethane materials and their applications in road engineering.The fundamental classification of bio-based polyurethane is introduced.The characteristics and challenges associated with various preparation methods for bio-based polyurethane are described.The influence of bio-based polyurethane on road engineering materials are analyzed.The evaluation indicators of bio-based polyurethane within the life cycle of road engineering are investigated.Finally,the development tendency towards in road engineering applications are forecasted.This paper provides a reference for the study of bio-based polyurethane materials in road engineering applications.
基金supported by the National Natural Science Foundation of China(32171734)the Scientific Research Funds of Huaqiao University(20BS201).
文摘Environment friendly and intelligent surfactants have attracted great attention in recent years.A bio-based CO_(2)responsive surfactant rosin acid dimaleimide choline(R-BMI-C)with an extremely rigid skeleton was prepared using rosin and choline as raw materials by Diels-Alder addition reaction and acid-base neutralization reactions.Its structure was confirmed by IR and^(1)H NMR spectra.The foams’properties of R-BMI-C could be adjusted by bubbling CO_(2)/N_(2)to change the structure of the surfactant.At pH 10.4,R-BMI-C forms an unstable foam with a half-life of 1.5 h.When the pH was reduced to 7.4 by bubbling CO_(2),R-BMI-C forms an extremely stable foam with a half-life of 336 h.The surfactant R-BMI-C changed from bola type to conventional type when bubbling CO_(2).And the internal aggregation structure of R-BMI-C aqueous solution changed from spherical micelles to laminar micelles according to the cryogenic-transmission electron microscope.We know that the lamellar structure tends to adsorb at the air/water interface or is trapped in the foam film,which slows down the foam coarsening and agglomeration process,resulting in a significant increase in foam stability.R-BMI-C could be used in oil extraction,fire-fighting and chemical decontamination due to its excellent foaming,stabilization and defoaming properties.
基金supported by the Science and Technology Research Project of Henan Province(222102230031)Key Scientific Research Projects of Colleges and Universities in Henan Province(23A430018)Natural Science Foundation of Henan(252300420267).
文摘The current global shortage of oil resources and the pollution problems caused by traditional barrier materials urgently require the search for new substitutes.Biodegradable bio-based barrier materials possess the characteristics of being renewable,environmentally friendly,and having excellent barrier properties.They have become an important choice in fields such as food packaging,agricultural film covering,and medical protection.This review systematically analyzes the design and research of this type of material,classifying biobased and biodegradable barrier materials based on the sources of raw materials and synthesis pathways.It also provides a detailed introduction to the latest research progress of biobased and biodegradable barrier materials,discussing the synthesis methods and improvement measures of their barrier properties.Subsequently,it analyzes the related technologies for enhancing the barrier properties of biobased and biodegradable barrier materials,and finally looks forward to the directions that future research should focus on,promoting the transition of biobased and biodegradable barrier materials from the laboratory to industrial applications.
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.
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.
文摘Aging plays a critical role in determining the durability and long-term performance of asphalt pavements,as it is influenced by both external factors(e.g.,temperature,ultraviolet(UV)radiation,moisture,oxidative gases)and internal factors such as binder composition.Although laboratory simulations of aging are well established for conventional bituminous binders,limited attention has been paid to replicating and evaluating aging processes in bio-based binders.This review provides a comprehensive analysis of current laboratory techniques for simulating and assessing binder aging,with a focus on two key areas:aging simulation protocols and evaluation methodologies.The analysis shows that although several efforts have been made to incorporate external aging factors into lab simulations,significant challenges persist,especially in the case of bio-based binders,which are characterized by a high variability in composition and limited understanding of their aging behavior.Current evaluation approaches also exhibit limitations.Improvements are needed in the molecular-level analysis of oxidation(e.g.,through more representative oxidation modelsin molecular dynamicssimulations),in the separation and quantification of binder constituents,and in the application of advanced techniques such as fluorescence microscopy to better characterize polymer dispersion.To enhance the reliability of laboratory simulations,future research should aim to improve the correlation between laboratory and field aging,define robust aging indexes,and refine characterization methods.These advancements are particularly critical for bio-based binders,whose performance is highly sensitive to aging and for which standard test protocols are still underdeveloped.A deeper understanding of aging mechanisms in both polymer-modified and biobased binders,along with improved analytical tools for assessing oxidative degradation and morphological changes,will be essential to support the development of sustainable,high-performance paving materials.
文摘In the context of transitioning toward more sustainable construction materials,this study explores the impact of incorporating millet husks as an alternative to sand on the physical,mechanical,and thermal performance of lightweight concrete.Through a mixture design approach,five formulations were selected and thoroughly characterized.The analysis of iso-response curves enabled an in-depth assessment of the cross-effects between formulation parameters and their interactions on the final properties of the material.The results show that integrating millet husks leads to a significant reduction in density,reaching up to 21%,while maintaining notable mechanical performance.A balanced formulation of sand and fibers achieved a maximum compressive strength of 12.11 MPa,demonstrating that,under specific conditions,plant fibers actively contribute to the structural integrity of the composite.In tensile strength,the positive influence of fibers is even more pronounced,with a maximum resistance of 8.62 MPa,highlighting their role in enhancing material cohesion.From a thermal perspective,millet husks reduce both thermal conductivity and effusivity,thereby limiting heat transfer and accumulation within the composite.Iso-response curve analysis reveals that these effects are directly linked to the proportions of the constituents and that achieving an optimal balance between sand,fibers,and cement is key to maximizing performance.These findings demonstrate that the adopted approach allows moving beyond conventional substitution methods by identifying optimal configurations for the design of lightweight bio-based concretes that are both strong and insulating,thereby confirming the potential of millet husks in developing lightweight concretes suitable for sustainable construction applications.
文摘An efficient and novel approach is proposed for oxidative arylation of bio-based furfuryl alcohol(FA)to aryl furans(AFs),a versatile monomer of photoelectric materials,in the presence of UiO-67-Pd(F)with phenanthroline/bipyridine,and poly-F substituted phenyl ligands as the mixture linkers.The results of control experiments and theoretical calculations reveal that the–F on the phenyl linkers efficiently tunes the electron-deficient nature of Pd through the Zr_(6) clusters bridges,which favors the adsorption and activation of the furan ring.Furthermore,the conjugation of different nitrogen-containing ligands facilitates Pd coordination for the Heck-type insertion and subsequent electrophilic palladation,respectively.As a result,the oxidative arylation of FA derivatives is substantially enhanced because of these electronic and steric synergistic effects.Under the optimized conditions,72.2%FA conversion and 74.8%mono aryl furan(MAF)selectivity are shown in the Heck-type insertion.Meanwhile,85.3%of MAF is converted,affording 74.8%selectivity of final product(AFs)in the subsequent electrophilic palladation reaction.This process efficiency is remarkably higher than that with homogeneous catalysts.In addition,furan-benzene polymer obtained from the halogen-free synthesis catalyzed by UiO-67-Pd(F)show significantly better properties than that from conventional Suzuki coupling method.Therefore,the present work provides a new insight for useful AFs synthesis by oxidative arylation of bio-furan via rational tunning the metal center micro-environment of heterogeneous catalyst.
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(22378181).
文摘The development of materials with excellent microwave absorption(MWA)and electromagnetic interference(EMI)shielding performances has currently received attention.Herein,mesophase pitch-based carbon foam(MPCF)with 3D interconnected pore structure was prepared through the high pressure pyrolysis of mesophase coal tar pitch.It is found that the 3D interconnected cellular pores of MPCF facilitate multiple reflections of electromagnetic waves,which results in the minimum reflection loss(RLmin)value of MPCF reaches-37.84 dB with the effective absorption bandwidth(EAB)of 5.44 GHz at a thickness of 2.70 mm,and the total average electromagnetic shielding effectiveness(SE_(T))under 3.00 mm thickness achieves 26.52 dB in X-band.Subsequently,MPCF is activated by KOH to obtain activated carbon foam(A-MPCF).The average SE_(T)of A-MPCF achieves 103.00 dB for abundant nanopores on the pore cell walls,which leads to a transition from the multiple reflections of electromagnetic waves on the walls to diffuse reflection.Unfortunately,the reflection coefficient(R)of A-MPCF increases from 0.78 to 0.90.To reduce the R value,Fe_(3)O_(4)/A-MPCF was fabricated via the in situ growth of nano Fe_(3)O_(4)on A-MPCF.Consequently,the R value of Fe_(3)O_(4)/A-MPCF was reduced from 0.90 to 0.74,whereas the MWA performance was only slightly decreased.This work proposes a simple strategy for simultaneously adjusting MWA and EMI shielding performances of materials.
基金the financial support from National Key Research and Development Plan(No.2017YFB0307901)the Canada Research Chairs program of the Government of Canada(No.CRC950213262)the Discovery Program of the Natural Sciences and Engineering Research Council of Canada(No.RGPIN-2022-03210).
文摘Biofoam products have attracted considerable attention lately because there is a growing demand for green/sustainable products.To this end,various biobased foams have either been developed or are currently in development,e.g.,bio-based polyurethanes(PUs),polylactic acid(PLA),starch,and polyhydroxyalkanotates(PHAs).Indeed,significant progress has been made;however,chal-lenges still persist,for example,biobased foam products have poor processability,inferior com-patibility,thermal and strength properties.In this review,we focus on five biofoam products:namely bio-based PUs,PLA,starch,PHAs,and cellulose biofoam products,along with their prop-erties and performance,as well as their manufacturing processes.Further efforts are still needed to unlock the full potential of these bio-based products and meet the goal of complementing and gradually replacing some of their fossil-based counterparts.Finally,the challenges,as well as arising opportunities of future research directions are discussed.
基金Funded by Shandong Provincial Youth Innovation Team Development Plan of Colleges and Universities(No.2022KJ100)National Natural Science Foundation of China(No.52172019)。
文摘Waste glass fibers were used as the main raw materials to prepare foamed glass-ceramics with 0-14 wt%H_(3)BO_(3)as a flux agent.The effects of H_(3)BO_(3)on the crystallization process,foaming behavior,and physical properties of CaO-MgO-Al_(2)O_(3)-SiO_(2)foamed glass-ceramics were investigated.The results showed that the main crystalline phase of the foamed glass-ceramics was anorthite with diopside as a minor crystalline phase,which exhibited a typical surface crystallization process.The addition of H_(3)BO_(3)modified the surface of glass powders and inhibited crystal precipitation obviously.The low melting point of H_(3)BO_(3)and the decrease of crystallinity jointly promoted the growth of pores,resulting in a reduction of bulk density and an increase in porosity.The compressive strength and thermal conductivity of the samples were linearly related to the bulk density.In particular,the sample added with 10 wt%H_(3)BO_(3)exhibited excellent properties,possessing a low coefficient of thermal conductivity 0.081 W/(m·K)and relatively high compressive strength 3.36 MPa.
基金financially supported by the National Natural Science Foundation of China(Nos.22475057 and No.52373262).
文摘Directional three-dimensional carbon-based foams are emerging as highly attractive candidates for promising electromagnetic wave absorbing materials(EWAMs)thanks to their unique architecture,but their construction usually involves complex procedures and extremely depends on unidirectional freezing technique.Herein,we propose a groundbreaking approach that leverages the assemblies of salting-out protein induced by ammonium metatungstate(AM)as the precursor,and then acquire directional three-dimensional carbon-based foams through simple pyrolysis.The electrostatic interaction between AM and protein ensures well dispersion of WC_(1−x)nanoparticles on carbon frameworks.The content of WC_(1−x)nanoparticles can be rationally regulated by AM dosage,and it also affects the electromagnetic(EM)properties of final carbon-based foams.The optimized foam exhibits exceptional EM absorption performance,achieving a remarkable minimum reflection loss of−72.0 dB and an effective absorption bandwidth of 6.3 GHz when EM wave propagates parallel to the directional pores.Such performance benefits from the synergistic effects of macroporous architecture and compositional design.Although there is a directional dependence of EM absorption,radar stealth simulation demonstrates that these foams can still promise considerable reduction in radar cross section with the change of incident angle.Moreover,COMSOL simulation further identifies their good performance in preventing EM interference among different electronic components.
基金from the Special Fund for the Program for Zhejiang Provincial Natural Science Foundation of China(LZ16C160001)National Key Research and Development Program(2017YFD0601105),the National Natural Science Foundation of China(Grant No.21806142)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LY20B070002).
文摘It is essential to design economic and efficient tougheners to prepare high-performance epoxy resin;however,this has remained a huge challenge.Herein,an eco-friendly,low-cost,and facile-fabricated bio-based hyperbranched toughener,carboxylic acid-functionalized tannic acid(CATA),was successfully prepared and applicated to the preparation of solvent-free epoxy resins.The mechanical performance,morphology,structural characterization,and thermal characterization of toughened epoxy resin system were studied.The toughened epoxy resin system with only 1.0wt%CATA reached the highest impact strength,111%higher than the neat epoxy resin system.Notably,the tensile strength and elongation at break of toughened epoxy resin systems increased moderately with increasing CATA loading.Nonphase-separated hybrids with significant toughening effect were obtained.Additionally,the thermal stabilities of toughened epoxy resin systems decreased with increasing CATA loading.This study provides an eco-friendly,cost-effective,and facile approach for the preparation of high-performance,solvent-free epoxy resins with potential for practical applications in sealing integrated circuits and electrical devices fields.
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the financial support provided by "One Hundred Talented People" of the Chinese Academy of Sciences–China (No. Y60707WR04)Natural Science Foundation of Zhejiang Province (No. Y16B040008)
文摘In this study, monoglycidyl silyl etherated eugenol(GSE) was synthesized as reactive epoxy diluent, and the chemical structure of GSE, intermediates, and products were characterized by Fourier transform infrared spectroscopy(FTIR) and nuclear magnetic resonance(~1 H-NMR). GSE existed as a potential bio-based reactive diluent for petroleum-based epoxy resin. The curing kinetics of EP/HHPA/GSE system was studied by non-isothermal DSC method. The kinetics parameters were calculated by using the Kissinger model, Crane model, Ozawa model, and β-T(temperature-heating rate) extrapolation, respectively. In addition, the effects of GSE on the thermo-mechanical properties and thermal stability of EP/HHPA/GSE systems were studied, indicating that GSE can effectively improve the toughness and thermal decomposition temperature of the epoxy system.
基金the National Key Research and Development Program of China(2017YFC1103900)the National Natural Science Foundation of China(22075244 and 51722306)+1 种基金Natural Science Foundation of Zhejiang Province(LZ22E030001)Shanxi-Zheda Institute of Advanced Materials and Chemical Engi-neering(2021SZ-TD009).
文摘Many natural fibers are lightweight and display remarkable strength and toughness.These properties originate from the fibers’hierarchical structures,assembled from the molecular to macroscopic scale.The natural spinning systems that produce such fibers are highly energy efficient,inspiring researchers to mimic these processes to realize robust artificial spinning.Significant developments have been achieved in recent years toward the preparation of high-performance bio-based fibers.Beyond excellent mechanical properties,bio-based fibers can be functionalized with a series of new features,thus expanding their sophisticated applications in smart textiles,electronic sensors,and biomedical engineering.Here,recent progress in the construction of bio-based fibers is outlined.Various bioinspired spinning methods,strengthening strategies for mechanically strong fibers,and the diverse applications of these fibers are discussed.Moreover,challenges in reproducing the mechanical performance of natural systems and understanding their dynamic spinning process are presented.Finally,a perspective on the development of biological fibers is given.
基金This work was financially supported by the following funds:National Natural Science Foundation of China(51803055)Hunan Provincial Natural Foundation of China(2019JJ50472)+5 种基金Scientific Research Fund of Hunan Provincial Education Department of China(18C0979,19A391)Opening Fund of National&Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources(KF201802)Hunan Province Key Field R&D Program Project(2019GK2246)Key Scientific Research Project of Huaihua University(HHUY2019-04)Hunan Provincial Key Research and Development Program(2018GK2062)Science and Technology Plan Project of Huaihua City(2020R3101).
文摘Polyvinyl alcohol (PVA) has been widely used in the fields of medical, food and packaging due to its excellentbiocompatibility, good fiber-forming and film-forming properties. However, the high flammability of PVA hasgreatly limited its wider applications. The flame-retardant PVA was prepared by melt blending of a bio-basedflame retardant (prepared from lignin, phosphoric acid and carbamide) with thermoplastic PVA (TPVA). Thechemical structure, morphology, thermal properties, mechanical properties, fire property and fluidity of thisflame retardant PVA were investigated by Fourier transform infrared spectrometer(FTIR), field emission scanning electron microscope(SEM), thermogravimetric analyzer(TGA), impact tester, universal testing machine,horizontal-vertical burning tester, limiting oxygen indexer(LOI) and melt flow rate meter(MFR). The resultsshowed that the prepared flame retardant had good compatibility with the PVA substrate;The impact strength,melt flow rate, fire property and char residue of this PVA material increased with the content of bio-based flameretardant. When the content of flame retardant was of 20%, the five indices including impact strength, meltflow rate, UL-94 level, LOI and char residual were 11.3 KJ/m^(2), 21.2 g/10 min, V-0 UL-94 level, 33.1%, and19.2%, respectively. This research can promote the high-value utilization of lignin and the application ofPVA in the fields of fire protection.
