Polyesters,as a class of high-performance and versatile polymer materials,often suffer from some drawbacks,such as hydrophobicity and brittleness due to their single structure nature.Thus,modifications have attracted ...Polyesters,as a class of high-performance and versatile polymer materials,often suffer from some drawbacks,such as hydrophobicity and brittleness due to their single structure nature.Thus,modifications have attracted much attention for enhancing their desirable properties,of which one efficient way is incorporating the aliphatic polyether segment into the main chain of the polyester.However,this approach is of much challenge because the obtained polyesters are problematic in either low alternating degree or low molecular weight.Herein,we describe an efficient strategy to incorporate polyether fragment into polyester by developing a novel Co-Al based heterodinuclear complex for mediating the copolymerization of propylene oxide(PO)withε-caprolactone(CL).The tracking experiments reveal that PO and CL convert into the polymer chain throughout the polymerization process.Especially,the linear increase in the molecular weight with conversion of CL indicates the controllable nature of the copolymerization.The competition polymerization,offering the monomer reactivity ratios of rCL=0.96 and rPO=1.04,suggests that the tendency of self-propagation or incorporation of monomers is nearly identical.interestingly,the obtained polymers with different ether contents exhibit tunable thermal properties with enhanced decomposition temperature for the polymer with higher ether content.The newly developed heterodinuclear complex for new polymerization provides an idea to synthesize new functional polymeric materials.展开更多
Copolymerization is a commonly employed method for optimizing the properties of polymer materials.Incorporating ether segments into polyesters main chain to obtain polyether-polyester copolymers is an effective strate...Copolymerization is a commonly employed method for optimizing the properties of polymer materials.Incorporating ether segments into polyesters main chain to obtain polyether-polyester copolymers is an effective strategy to realize the integration of multiple properties of polyester and polyether,and to develop more high-performance,multi-purpose polymer materials.Herein,the synthesis of poly(ether-ester)s is accessible by employing the biphenyl-linked heterodinuclear salen Cr-AI complex in the presence of PPNCI for the copolymerization of epoxides and£-caprolactone(CL).Monitoring the copolymerization process reveals that catalyst 1 exhibited good performance for the copolymerization of epoxides and CL,affording copolymers with a gradient sequence structure.The dynamic thermomechanical analysis(DMA)study indicates the obtained poly(ether-ester)s possess enhanced flexibility compared with the block copolymers or blend of PPO and PCL homopolymers with the same ratio.This study provides a theoretical basis for the preparation of high-performance polymer materials.展开更多
基金the National Natural Science Foundation of China(Nos.21722402 and 21674015)the Fundamental Research Funds for the Central Universities(No.DUT18ZD105).
文摘Polyesters,as a class of high-performance and versatile polymer materials,often suffer from some drawbacks,such as hydrophobicity and brittleness due to their single structure nature.Thus,modifications have attracted much attention for enhancing their desirable properties,of which one efficient way is incorporating the aliphatic polyether segment into the main chain of the polyester.However,this approach is of much challenge because the obtained polyesters are problematic in either low alternating degree or low molecular weight.Herein,we describe an efficient strategy to incorporate polyether fragment into polyester by developing a novel Co-Al based heterodinuclear complex for mediating the copolymerization of propylene oxide(PO)withε-caprolactone(CL).The tracking experiments reveal that PO and CL convert into the polymer chain throughout the polymerization process.Especially,the linear increase in the molecular weight with conversion of CL indicates the controllable nature of the copolymerization.The competition polymerization,offering the monomer reactivity ratios of rCL=0.96 and rPO=1.04,suggests that the tendency of self-propagation or incorporation of monomers is nearly identical.interestingly,the obtained polymers with different ether contents exhibit tunable thermal properties with enhanced decomposition temperature for the polymer with higher ether content.The newly developed heterodinuclear complex for new polymerization provides an idea to synthesize new functional polymeric materials.
基金the National Natural Science Foundation of China(Nos.21722402 and 21674015).
文摘Copolymerization is a commonly employed method for optimizing the properties of polymer materials.Incorporating ether segments into polyesters main chain to obtain polyether-polyester copolymers is an effective strategy to realize the integration of multiple properties of polyester and polyether,and to develop more high-performance,multi-purpose polymer materials.Herein,the synthesis of poly(ether-ester)s is accessible by employing the biphenyl-linked heterodinuclear salen Cr-AI complex in the presence of PPNCI for the copolymerization of epoxides and£-caprolactone(CL).Monitoring the copolymerization process reveals that catalyst 1 exhibited good performance for the copolymerization of epoxides and CL,affording copolymers with a gradient sequence structure.The dynamic thermomechanical analysis(DMA)study indicates the obtained poly(ether-ester)s possess enhanced flexibility compared with the block copolymers or blend of PPO and PCL homopolymers with the same ratio.This study provides a theoretical basis for the preparation of high-performance polymer materials.
