Polymer ( IF 4.6 ) Pub Date : 2020-07-22 , DOI: 10.1016/j.polymer.2020.122797 Chuanli Ren , Xun Zhu , Na Zhao , Sha Fang , Zhibo Li
A new polystyrene supported cyclic trimeric phosphazene base (PS-CTPB) was designed and synthesized. It was demonstrated that hypotoxic poly (ε-caprolactone) (PCL) can be directly prepared via ring-opening polymerization (ROP) by using PS-CTPB as catalyst. The PS-CTPB catalyst was prepared via immobilization of cyclic trimeric phosphazene base (CTPB) moiety on polystyrene microspheres to obtain a heterogeneous organocatalyst. The composition and chemical structure of the heterogeneous PS-CTPB was systematically characterized using solid-state 13C and 31P MAS NMR, FTIR, SEM and element analysis. It was found that immobilization of CTPB on PS microsphere maintained its excellent catalytic activity for ROP of ε-CL, δ-valerolactone (δ-VL), rac-lactide (rac-LA). Moreover, the heterogeneous PS-CTPB could be easily separated or recycled via simple filtration. Given that, the obtained polyesters contained negligible catalyst residual, so the obtained PCL samples have low cytotoxicity indicated from MTT assay. It was worth noting that the recycled PS-CTPB catalyst could be reused for another six consecutive cycles without significant decrease of catalytic activity.
中文翻译:
使用可回收的聚苯乙烯负载的环状三聚磷腈碱作为催化剂,通过开环聚合直接制备低毒的聚酯
设计并合成了一种新型的聚苯乙烯负载的环状三聚磷腈碱(PS-CTPB)。结果表明,以PS-CTPB为催化剂,可通过开环聚合(ROP)直接制备低毒的聚(ε-己内酯)(PCL)。PS-CTPB催化剂是通过将环状三聚磷腈碱(CTPB)部分固定在聚苯乙烯微球上制备的,从而获得非均相有机催化剂。使用固态13 C和31 P MAS NMR,FTIR,SEM和元素分析系统地表征了异质PS-CTPB的组成和化学结构。发现将CTPB固定在PS微球上对ε -CL,δ的ROP保持了优异的催化活性。-戊内酯(δ - VL ),外消旋-丙交酯(外消旋-LA)。而且,通过简单过滤可以很容易地分离或回收异质PS-CTPB。鉴于此,所获得的聚酯含有可忽略的催化剂残留,因此所获得的PCL样品具有低的MTT分析表明的细胞毒性。值得注意的是,回收的PS-CTPB催化剂可以再使用六个连续的周期,而不会明显降低催化活性。