Comprehensive Summary,As a typical type of sustainable plastic,polyesters can be recycled or upcycled into value-added chemicals in a variety of methods.However,excess reagents are required for most of the depolymeriz...Comprehensive Summary,As a typical type of sustainable plastic,polyesters can be recycled or upcycled into value-added chemicals in a variety of methods.However,excess reagents are required for most of the depolymerization and upcycling processes,causing the emission of environmental pollutants and the waste of chemical resources.Here we demonstrate a one-pot catalytic process to directly crack polylactic acid into acrylic acid by acid catalyst with the assistance of an ionic liquid,Bu4PBr.Polylactic acid is attacked by the Br–from Bu4PBr and the H+from acid to form oligomers containing Br or acryloyl group,and these oligomers serve as intermediates to produce acrylic acid during their mutual transformation.The acrylic acid is vaporized directly from the reactor and obtained in a collector with a selectivity around 90%when polylactic acid is fully converted.This green process shows great advantages in atom economy compared to the conventional recycling/upcycling methods for polyesters,in addition.展开更多
A new entire biodegradable scaffold has been developed which does not require precellularization before transplantation.This new kind of vascular scaffold prototype made from porous poly-ε-caprolactone( PCL) membrane...A new entire biodegradable scaffold has been developed which does not require precellularization before transplantation.This new kind of vascular scaffold prototype made from porous poly-ε-caprolactone( PCL) membrane to provide three-dimensional environment for cell growth, and embedded with weft-knitted polylactic acid( PLA) fabric to support mechanics.The aim of this paper is to study the variation tendency of mechanical properties with the fabric spacing changing.The basic geometrical parameters were measured to characterize properties of the samples.The tensile and compressive elastic recovery of the samples were tested by the universal mechanical tester and radial compression apparatus,respectively.Both tensile and compressive properties enhanced when reducing the fabric spacing of the composite vascular scaffold.展开更多
基金financial support from the National Natural Science Foundation of China(22072002,21932002,21821004)China National Petroleum Corporation-Peking University Strategic Cooperation Project of Fundamental Research.D.M.acknowledges support from the Tencent Foundation through the XPLORER.PRIZE.
文摘Comprehensive Summary,As a typical type of sustainable plastic,polyesters can be recycled or upcycled into value-added chemicals in a variety of methods.However,excess reagents are required for most of the depolymerization and upcycling processes,causing the emission of environmental pollutants and the waste of chemical resources.Here we demonstrate a one-pot catalytic process to directly crack polylactic acid into acrylic acid by acid catalyst with the assistance of an ionic liquid,Bu4PBr.Polylactic acid is attacked by the Br–from Bu4PBr and the H+from acid to form oligomers containing Br or acryloyl group,and these oligomers serve as intermediates to produce acrylic acid during their mutual transformation.The acrylic acid is vaporized directly from the reactor and obtained in a collector with a selectivity around 90%when polylactic acid is fully converted.This green process shows great advantages in atom economy compared to the conventional recycling/upcycling methods for polyesters,in addition.
基金the Fundamental Research Funds for the Central Universities,China，National Natural Science Foundation of China，"111 Project" Biomedical Textile Materials Science and Technology,China，the Donghua University Innovation Fund of Graduate Project,China
文摘A new entire biodegradable scaffold has been developed which does not require precellularization before transplantation.This new kind of vascular scaffold prototype made from porous poly-ε-caprolactone( PCL) membrane to provide three-dimensional environment for cell growth, and embedded with weft-knitted polylactic acid( PLA) fabric to support mechanics.The aim of this paper is to study the variation tendency of mechanical properties with the fabric spacing changing.The basic geometrical parameters were measured to characterize properties of the samples.The tensile and compressive elastic recovery of the samples were tested by the universal mechanical tester and radial compression apparatus,respectively.Both tensile and compressive properties enhanced when reducing the fabric spacing of the composite vascular scaffold.
