Direct melt/solid polycondensation of lactic acid(LA)was carried out to obtain high molecular weight poly(lactic acid)(PLA)by a process using various catalysts in the first-step melt polycondensation,and followed soli...Direct melt/solid polycondensation of lactic acid(LA)was carried out to obtain high molecular weight poly(lactic acid)(PLA)by a process using various catalysts in the first-step melt polycondensation,and followed solid polycondensation by using p-toulenesulfonic acid monohydrate(TSA)as the catalyst in the second step.Effects of various catalysts and reaction temperature on the molecular weight and crystallinity of resulting PLA polymers were examined.It was shown that SnCl_2·2H_2O/TSA,SnCl_2·2H_2O/succinic ...展开更多
It is of great interest to make a degradable material widely tailorable to replace petroleum-derived products among diverse applications.Here,we report the construction of a new multi-purpose degradable material for t...It is of great interest to make a degradable material widely tailorable to replace petroleum-derived products among diverse applications.Here,we report the construction of a new multi-purpose degradable material for the first time via a simple ternary copolymerization system comprisingε-caprolactone(ε-CL),cyclohexane oxide(CHO)and CO_(2).Under low pressure of 1 bar∼5 bar,the ring-opening polymerization(ROP)ofε-CL and ring-opening copolymerization(ROCOP)of CO_(2) and CHO can simultaneously proceed.The carbonate units are randomly distributed on the polymer chain.These random terpolymers have controllable molar mass(10-106 kDa)and compositions(4-33 mol%CO_(2)).And the obtained materials show large-span tunability from tough plastic to elastomer and even adhesive.展开更多
基金Program for Changjiang Scholars and Innovative Research Team in University(No: IRT0540 )Innovation fund for technology based firms, MOST(05C26223600922)
基金the HMPURT(No.2006KYCX009)the National Natural Science Foundation of Henan(No.200510465008)Henan Innovation Project(No.0523021300)
文摘Direct melt/solid polycondensation of lactic acid(LA)was carried out to obtain high molecular weight poly(lactic acid)(PLA)by a process using various catalysts in the first-step melt polycondensation,and followed solid polycondensation by using p-toulenesulfonic acid monohydrate(TSA)as the catalyst in the second step.Effects of various catalysts and reaction temperature on the molecular weight and crystallinity of resulting PLA polymers were examined.It was shown that SnCl_2·2H_2O/TSA,SnCl_2·2H_2O/succinic ...
基金funded by the National Key R&D Program of China(No.2021YFA1501700)the Science and Technology Development Plan of Jilin Province(Nos.20230101042JC,20210201059GX)+2 种基金the National Natural Science Foundation of China,Basic Science Center Program(No.51988102)the National Natural Science Foundation of China(Nos.52203017,52073272 and 22293062)Bureau of International Cooperation Chinese Academy of Sciences(No.029GJHZ2023017MI).
文摘It is of great interest to make a degradable material widely tailorable to replace petroleum-derived products among diverse applications.Here,we report the construction of a new multi-purpose degradable material for the first time via a simple ternary copolymerization system comprisingε-caprolactone(ε-CL),cyclohexane oxide(CHO)and CO_(2).Under low pressure of 1 bar∼5 bar,the ring-opening polymerization(ROP)ofε-CL and ring-opening copolymerization(ROCOP)of CO_(2) and CHO can simultaneously proceed.The carbonate units are randomly distributed on the polymer chain.These random terpolymers have controllable molar mass(10-106 kDa)and compositions(4-33 mol%CO_(2)).And the obtained materials show large-span tunability from tough plastic to elastomer and even adhesive.
