新型两亲性生物降解接枝共聚物的性能

对新型的两亲性生物降解接枝共聚物羟丙基纤维素接枝聚己内酯(HPC-g-PCL)的综合性能进行了测试。X射线衍射结果表明,接枝共聚有效地降低了PCL的结晶度,且随着PCL链段含量的降低,接枝共聚物的结晶度相应下降。DSC结果表明,与PCL均聚物相比,所得接枝共聚物的Tm、Tc和Xc均明显降低,且随着PCL链段含量的降低而不断下降;同时,与先熔融后冷却相比,室温下的共聚物溶液浇注膜,其结晶程度更完善。水解降解实验结合GPC曲线和SEM照片结果表明,与均聚物PCL相比,接枝共聚物更易发生降解。

STUDY ON PROPERTIES OF AMPHIPHILIC BIODEGRADABLE COPOLYMER THE HYDROXYPROPYL CELLULOSE-GRAFT-POLYCAPROLACTONE

The properties of the amphiphilic hydroxypropyl cellulose graft polycaprolactone(HPC-g-PCL) copolymers were investigated.The results of WAXD and DSC measurements show that grafting of PCL onto HPC backbone gives rise to a very effective decrease in the crystallinity,and consequently the T_m and T_c of the graft copolymers also decrease,comparison of that of PCL homopolymer.It is also found that the lower the D_p,the lower the X_c,T_m and T_c.The hydrolysis degradation of the graft copolymers was investigated in buffer in vitro and compared with that PCL homopolymer.The degradation rates of the graft copolymers were significantly larger than that of PCL,due to decreases in the crystallinity of the PCL segment by the introduction of a hydrophilic HPC unit and its branched structure.