摘要
以单质碲、硼氢化钠和溴丙醇为原料合成了一种羟基功能化的双碲化合物,即2,2'-二碲二丙醇((HOC3H6Te)2);以(HOC3H6Te)2为引发剂,在脂肪酶Novozym435的催化作用下,分别引发己内酯(ε—CL)和1,3-二恶烷-2-酮(TMC)开环聚合,制备了含双碲聚己内酯((PCLTe)2)和含双碲聚碳酸酯((PTMCTe)2),并利用^1H-NMR、^125Te—NMR对其结构进行表征.以联苯二碲(PhTe)2、(PCLTe)2为研究对象,利用^1H-NMR、^13C-NMR、^125Te-NMR探究了含双碲聚合物的动态性能.结果表明,在避光和室温条件下,(PhTe)2与(PCLTe)2能立即发生双碲键的相互交换反应,并瞬间达到反应平衡.利用125Te-NMR、飞行时间质谱(MALDI—TOF—MS)证明了在没有外界刺激的条件下,(PCLTe)2与(PTMCTe)2之间可以发生相互交换反应,并产生了嵌段共聚物(PCLTeTePTMC),这种嵌段共聚物极大地提高了(PCLTe)2与(PTMCTe)2之间的相容性,并改善了(PCLTe)2/(PTMCTe)2共混薄膜的力学性能.
Dynamic covalent polymers that inherit the reversibility and robustness of dynamic covalent bonds have attracted considerable attention in terms of self-healing,stimuli-responsiveness,and recyclability.However, most of them require an external stimulus to induce their dynamic properties,which may limit their application. Here,two dynamic covalent polymers based on ditelluride bonds were prepared,which were free of external conditions.First,a novel stable ditelluride-containing compound,di-(1-hydroxypropyl)ditelluride((HOC3H6Te)2) was synthesized.Then,two ditelluride-containing polymers,polycaprolactone(PCLTe)2and poly(1,3- trimethylene carbonate)(PTMCTe)2were synthesized via the enzymatic ring-opening polymerization using (t-IOC3H6Te)2as the initiator and Novozym435as the catalyst.The structures of(PCLTe)2and(PTMCTe)2were verified by^1H-NMR and^125Te-NMR.The dynamic properties of the ditelluride-containing polymers were investigated using(PCLTe)2and(PTMCTe)2as the model polymers and confirmed by^1H-NMR,^13C-NMR and ^125Te-NMR spectra.The results indicated that the ditelluride exchange between(PCLTe)2and diphenyl ditelluride ((PhTe)2)could occur spontaneously in the dark at room temperature without any external stimuli and the equilibrium of the reaction could be reached immediately.The dynamic exchange between(PCLTe)2and (PTMCTe)2was confirmed by ^125Te-NMR spectrum and MALDI-TOF mass,which could occur spontaneously without any external stimuli.The results of MALDI-TOF mass showed that a di-block polymer(PTMCTeTePCL) was formed during the exchange process;The tensile test results indicated that the tensile strength and the elongation of PCL/PTM Ccomposite were3.07MPa and38.26%,respectively.However,as for (PCLTe)J(PTMCTe)2composite,the tensile strength and the elongation were increased to 5.22MPa and 80.51%, respectively.The scanning electron microscopy images showed that the compatibility between(PCLTe)2and (PTMCTe)2was significantly improved comparing with the PCL/PTMC composite.The results indicated that the ditelluride exchange had a great effect on the properties of(PCLTe)2/(PTMCTe)2composite.This study developed the ditelluride-related dynamic chemistry and promoted the application of dynamic covalent polymers.
作者
刘佳
马晓宁
郎美东
Jia Liu;Xiao-ning Ma;Mei-dong Lang(Shanghai Key Laboratory of Advanced Polymeric Materials,Key Laboratory for Ultrafine Materials of Ministry of Education,School of Materials Science and Engineering,East China University of Science and Technology,Shanghai200237)
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2018年第12期1514-1523,共10页
Acta Polymerica Sinica
基金
国家重点研发计划(项目号2016YFC1100703)资助
关键词
双碲键
动态共价键
酶催化
嵌段共聚物
Ditelhtride bonds
Dynamic covalent polymer
Enzymatic polymerization
Di-block polymer
