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Special Topic on Bio-based and Biodegradable Polymers

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Science China Chemistry 2016年第11期59卷 1353-1354页

作者： yu-zhong wang yun-Xuan Weng State Key Laboratory of Polymer Materials Engineering National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan) College of Chemistry Sichuan University School of Materials and Mechanical Engineering Beijing Technology and Business University

In the past decades,bio-based and biodegradable polymers have attracted wide and increasing interests because of the shortage of fossil resource,concerns on environmental pollution,demands for some medical fields as well as support of government *** on the sustainable source of organic carbon,biodegradability and biocompatibility,these polymers have shown promising applications in industry,agriculture,biomedicine and daily *** impart excellent physical properties and functions to them,scientists and engineers have exploited versatile methods to tune

关键词： biodegradable sustainable fossil shortage agriculture versatile contributions interests polymerization controllable

Controlled synthesis and closed-loop chemical recycling of biodegradable copolymers with composition-dependent properties

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Science China Chemistry 2022年第5期65卷 943-953页

作者： Yi-Teng Yan Gang Wu Si-Chong Chen yu-zhong wang The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE) National Engineering Laboratory ofEco-Friendly Polymeric Materials(Sichuan)State Key Laboratory of Polymer Materials EngineeringCollege of ChemistrySichuan UniversityChengdu 610064China

The closed-loop recycling concept of the polymer wastes into building-block chemicals is attractive,but the closed-loop recycling of copolymers enabled by energy-efficient chemical recycling and cost-effective separations is still facing great ***,for the first time,a one-pot sequential copolymerization of γ-butyrolactone(γ-BL) and p-dioxanone(PDO)using an economical ureas/alkoxides catalytic system is conducted to synthesize biodegradable and chemically recyclable poly-(γ-butyrolactone)-block-poly(p-dioxanone)(PγBL-b-PPDO) diblock copolymers with well-defined and controlled *** composition-dependent properties of PγBL-b-PPDO copolymers,including thermal properties and crystallization behavior,are *** results show that the thermal stability and crystalline ability of PγBL are enhanced observably by introducing the PPDO ***,the PγBL-b-PPDO copolymers can be depolymerized efficiently into the corresponding co-monomers with a yield of over 95% by simply low-temperature pyrolysis under ***,γ-BL and PDO monomers are selectively separated with an isolated purity of about 99% based on the difference in their physicochemical ***,their repolymerization is realized to obtain the copolymers with nearly identical structures and thermostability,demonstrating the closed-loop recycling of copolymers,i.e.,*** research provides important guidance for the design of novel sustainable polymers towards more efficient chemical recycling,separation and regeneration.

关键词： biodegradable copolyester poly(p-dioxanone) tunable properties closed-loop chemical recycling

Chemically recyclable copolyesters from bio-renewable monomers:controlled synthesis and composition-dependent applicable properties

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Science China Chemistry 2023年第7期66卷 2062-2069页

作者： Wan-Ting Xiong Gang Wu Si-Chong Chen yu-zhong wang The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE) National Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan)State Key Laboratory of Polymer Materials EngineeringCollege of ChemistrySichuan UniversityChengdu 610064China

The development of chemically recyclable polymers is a promising solution to address the dual challenges of the environment and resources caused by petroleum-based *** recent advancements,it is highly desirable for developing recyclable polymers to meet the requirements of both practical uses and well-performed ***-renewable monomers have been paid great attention recently as promising potential candidates for establishing a sustainable circular polymer ***,a sequential copolymerization of various bio-renewable n-alkyl substituted δ-valerolactone((R)VLs)and p-dioxanone(PDO)is conducted to synthesize novel chemically recyclable diblock copolymers poly(p-dioxanone)-block-poly(n-alkyl-valerolactones)(PPDO-b-P(R)VLs)with well-defined and controlled *** properties of copolymers including thermal property,crystallization,mechanical property,hydrophilicity and transport property can be tuned effectively to meet the requirements of practical uses by alternating the alkyl substituents(R)and the P(R)VLs *** addition,the high-efficiency and facile chemical recycling of copolymers to PDO and(R)VL comonomers is realized with a high yield of>96.5%and a high purity of 99%.

关键词： bio-renewable monomers ring-opening polymerization block copolyester tunable properties chemical recyclability

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SYNERGISTIC EFFECTS OF NOVOLAC-BASED CHAR FORMER WITH A PHOSPHORUS/NITROGEN-CONTAINING FLAME RETARD ANT IN POLYAMIDE 6

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Chinese Journal of Polymer Science 2012年第1期30卷 72-81页

作者： Wei-cheng Xiong Li Chen De-yi wang Fei Song yu-zhong wang Center for Degradation an-d Flame--Retardant Polymeric Materials College of-Chemistry State Key Laboratory of Polymer Materials Engineering National Engineering Laboratory of Eco-Friendly Polymeric Materials （Sichuan） Sichuan University Chengdu 610064 China

The synergistic effect of phosphorus oxynitride（PON） with a novolac-based char former modified by salification （NA-metal salt） on the flame retardance of polyamide 6（PA6） was *** this purpose,various flame-retardant PA6 systems were melt-compounded with PON,PON/NA,PON/NA-V_2O_5 and PON/NA-Fe_2O_3,and their flame retardance was evaluated by measuring the limiting oxygen index（LOI） values and UL-94 vertical burning *** results showed that,compared with the PA6/PON/NA system,the combination of two char formers（NA-V_2O_5,NA-Fe_2O_3） with PON could obviously improve the char formation and flame retardance of *** flame retardance and cone calorimetric analyses showed the stronger synergism as well as the better flame retardant performance of PON/NA-Fe_2O_3 flame retardant system. The effects of different char formers on the flame retardance and thermal stability of this system were also discussed.

关键词： Polyamide Flame retardance Novolac resin Synergistic effect

Bio-based removable pressure-sensitive adhesives derived from carboxyl-terminated polyricinoleate and epoxidized soybean oil

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Chinese Chemical Letters 2021年第2期32卷 875-879页

作者： yu-Fei Lei Xiao-Lin wang Bo-Wen Liu Li Chen yu-zhong wang The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE) National Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan)State Key Laboratory of Polymer Materials EngineeringCollege of ChemistrySichuan UniversityChengdu 610064China

A novel kind of fully bio-based PSAs we re obtained through the curing reaction between two components derived from the plant oils:carboxyl-terminated polyricinoleate(PRA) fro m the castor oil and epoxidized soybean oil(ESO).The get content,glass transition temperature(Tg),rheological behavior,tensile strength,creep resistance and 180° peel strength of the PSAs were feasibly tailored by adjusting the component ratio of ESO to *** low cross-linking level,the PSAs behaved like a viscous liquid and did not possess enough cohesiveness to sustain the mechanical stress during peeling,The PSAs cross-linked at or near the optimal stoichiometric conditions displayed an adhesive(interfacial) failure between the substrate and the adhesive layer,which were associated with the lowest adhesion *** PSAs with the dosage amount of ESO ranging from 10.20 wt% were tacky and flexible,which exhibited 1800 peel strength ranging from 0.4~2.3 N/cm;and could be easily removed without any residues on the *** process for the preparation of the fully bio-based PSAs was environmentally friendly without using any orga nic solve nt or other toxic chemical,herein showing the great potential as sustainable materials.

关键词： Pressure sensitive adhesive Polyricinoleate Epoxidized soybean oil Viscoelasticity Removability

From trash to treasure: Chemical recycling and upcycling of commodity plastic waste to fuels, high-valued chemicals and advanced materials

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Journal of Energy Chemistry 2022年第6期31卷 369-388,I0011页

作者： Fan Zhang Fang wang Xiangyue Wei Yang Yang Shimei Xu Dehui Deng yu-zhong wang The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE) National Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan)College of ChemistrySichuan UniversityChengdu 610064SichuanChina College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610064SichuanChina State Key Laboratory of Catalysis Collaborative Innovation Center of Chemistry for Energy MaterialsDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina

Of all the existing materials, plastics are no doubt among the most versatile ones. However, the extreme increases in plastic production as well as the difficulty of the material for degradation have led to a huge number of plastic wastes. Their recycling rate after disposal is less than 10%, resulting in a series of serious environmental and ecological problems as well as a significant waste of resources. Current recycling methods generally suffer from large energy consumption, the low utilization rate of recycled products with low added value, and produce other waste during the process. Here, we summarized recentlydeveloped chemical recycling ways on commodity plastics, especially new catalytic paths in production of fuels, high-valued chemicals and advanced materials from a single virgin or a mixture of plastic waste,which have emerged as promising ways to valorize waste plastics more economically and environmentally friendly. The new catalyst design criteria as well as innovative catalytic paths and technologies for plastic upcycling are highlighted. Beyond energy recovery by incineration, these approaches demonstrate how waste plastics can be a viable feedstock for energy use with the generation of clean H_(2), high-quality liquid fuels and materials for energy storage, and help inspiring more catalytic process on plastic upcycling to overcome the economical hurdle and building a circular plastic economy.

关键词： Chemical recycling Upcycling Commodity plastic Sustainable development Catalytic path

Porous carbon/Fe composites from waste fabric for high-efficiency electromagnetic wave absorption

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Journal of Materials Science & Technology 2022年第31期126卷 266-274页

作者： Jin-Bo Cheng Hai-Bo Zhao Ai-Ning Zhang Yan-Qin wang yu-zhong wang Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE) State Key Laboratory of Polymer Materials EngineeringNational Engineering Laboratory for Eco-Friendly Polymer Materials(Sichuan)College of ChemistrySichuan UniversityChengdu 610064China

Nowadays,a large amount of waste fabrics has brought huge environmental and resource problems,while the traditional recycling routes are downcycling with low efficiency and complex separation ***,we demonstrate a green and facile route to up-recycle waste fabrics(cotton-polyester blending or cotton fabrics)into a high-performance microwave *** this design,an assistant coating was deposited onto the fiber surface of the waste fabric through the assembly of tannic acid-Fe^(2+)(TA-Fe^(2+)),which effectively catalyzed the polymer fiber into highly graphitized porous carbon fiber at high ***,the Fe nanoparticles from the reduction of Fe^(2+)ions were evenly embedded on the surface of porous carbon ***,the resultant porous carbon/Fe composites with hierarchi-cal microstructures displayed excellent microwave absorption ***,the microwave ab-sorber from waste polyester-cotton blended fabric could reach a minimum reflection loss(RL)of-50.5 dB at a thin coating thickness of 1.7 mm,and the minimum RL from waste cotton fabric absorber reached-47.1 dB at a thickness of 2.5 *** work provides a new idea to convert waste fabrics into high value-added microwave absorbing materials in a simple and environmentally friendly way,which will help reuse resources and protect the environment.

关键词： Up recycling Microwave absorption Waste fabrics Thin thickness

Design and synthesis of liquid crystal copolyesters with high-frequency low dielectric loss and inherent flame retardancy

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Chinese Chemical Letters 2023年第5期34卷 621-625页

作者： Shi-yu Zhang Teng Fu yue Gong De-Ming Guo Xiu-Li wang yu-zhong wang State Key Laboratory of Polymer Materials Engineering The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric MaterialsNational Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan)College of ChemistrySichuan UniversityChengdu 610064China

Ultra-low dielectric loss(Df)and low dielectric constant(Dk)materials are urgently required in highspeed and large-capacity transmission,in which the wholly aromatic liquid crystal polymer(LCP)has gained attention due to its excellent dielectric ***,the relationship between molecular structure and dielectric properties is still not *** this study,two copolyesters containing phenyl or naphthyl structures are synthesized,as well as the effects of benzene and naphthalene mesogens on dielectric properties are *** synthesized copolyesters containing naphthalene structure have good comprehensive properties with high thermal stability(T_(5%)=479℃ and T_g=195-216℃),inherent flame retardance(LOI=33.0-35.0 and UL-94 V-0 level at 0.8 mm),low Dk(2.9-3.0@10 GHz)and low Df(0.0027-0.0047@10 GHz).Naphthalene mesogen can reduce the dielectric loss more significantly than benzene at high frequency by reducing the density and mobility of polarizable groups,which leads to the effectively limited dipole polarization in ***,we proposed a new strategy for designing low Dk and low Df materials.

关键词： Liquid crystal polymer Low dielectric loss Low dielectric constant Naphthalene structure Flame retardant

Graphite-polypyrrole coated 316L stainless steel as bipolar plates for proton exchange membrane fuel cells

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International Journal of Minerals,Metallurgy and Materials 2011年第1期18卷 53-58页

作者： Li-jun Yang Hai-jun yu Li-jun Jiang Lei Zhu Xu-yu Jian zhong wang Energy Materials and Technology Research Institute Beijing General Research Institute for Nonferrous Metals Beijing 100088 China

316L stainless steel（SS 316L） is quite attractive as bipolar plates in proton exchange membrane fuel cells（PEMFC）.In this study,graphite-polypyrrole was coated on SS 316L by the method of cyclic *** surface morphology and chemical composition of the graphite-polypyrrole composite coating were investigated by scanning electron microscopy（SEM） and X-ray photoelectron spectroscopy（XPS）.A simulated working environment of PEMFC was applied for testing the corrosion properties of graphite-polypyrrole coated SS *** current densities in the simulated PEMFC anode and cathode conditions are around 3×10-9 and 9×10-5 A·cm-2,*** addition,the interfacial contact resistance（ICR） was also *** ICR value of graphite-polypyrrole coated SS 316L is much lower than that of bare SS ***,graphite-polypyrrole coated SS 316L indicates a great potential for the application in PEMFC.

关键词： proton exchange membrane fuel cells polypyrrole graphite corrosion contact resistance stainless steel