高分子量六臂星型聚丙交酯的制备与降解性能

Synthesis and degradation of high molecular weight six-arm star polylactide

以D-山梨醇为核,辛酸亚锡为催化剂,高纯度的D,L-丙交酯(D,L-LA)为单体,通过阳离子开环聚合,得到了一系列六臂星型聚丙交酯(sPLA),产物结构通过红外光谱(FTIR)和核磁共振(1H NMR)表征。凝胶渗透色谱-激光散射联用技术(GPC-MALLS)测定聚合物分子量显示:通过控制D-山梨醇与D,L-LA的加料比,可达到有效调控产物分子量的目的;当D-山梨醇用量为0.02%时,产物数均分子量可达2.97×105;产物分子量分布较窄,约为1.1～1.2。在酸性、中性、碱性等缓冲液中的降解表明,sPLA的降解速率明显快于线型PLA。

A series of star PLAs were synthesized by cation ring opening polymerization of highly purified D,L-LA,using D-sorbitol as core and stannous octanoate as catalyst,and the structure was characterized by FTIR and 1H NMR spectra.GPC-MALLS determination showed： the molecular weight of star polymers can be effectively controlled via the feed ratio of D-sorbitol/D,L-LA;when D-sorbitol was 0.02%,the number-average molecular weight of sPLA was up to 2.97×105;the distribution of molecular weight was narrow and about 1.1～1.2.The degradation tests in acidic,neutral or basic buffer solutions indicated that the degradation rate of sPLA was much more rapid than that of linear PLA.