两亲性星型共聚物s-PLLA-PVP的制备及性能

以木糖醇为引发剂,辛酸亚锡催化L-丙交酯开环聚合制备星型聚乳酸(s-PLLA);以N-乙烯吡咯烷酮(NVP)为单体、偶氮二异丁腈(AIBN)为引发剂,通过自由基溶液聚合法得到末端羧基化的聚乙烯基吡咯烷酮(PVP-COOH);再通过s-PLLA和PVP-COOH发生酯化反应制备两亲性星型共聚物s-PLLA-PVP.用FTIR、~1H NMR、GPC对s-PLLA-PVP的结构进行表征.用XRD、TGA和DSC研究共聚物s-PLLA-PVP的结晶性能和热学性能,通过接触角测定仪测试共聚物薄膜的亲水性能.结果表明,随着s-PLLA分子量的增加,s-PLLA-PVP共聚物热学性能提高;PVP的引入,降低了共聚物的结晶性能,提高了共聚物的亲水性能.

Preparation and properties of amphiphilic star-shaped s-PLLA-PVP copolymers

The star-shaped poly (L-lactide)(s-PLLA)was synthesized via the ring-opening polymerization of L-lactide with xylitol as a multifunctional initiator and stannous octoate as a catalyst.The carboxylic polyvinyl pyrrolidone group (PVP-COOH)was synthesized by free radical solution polymerization with N-vinyl pyrrolidone (NVP)as monomers and azodiisobutyronitrile (AIBN)as an initiator.The amphiphilic star-shaped s-PLLA-PVP copolymers were then synthesized using esterification reaction between the hydroxy group of s-PLLA and the carboxyl group of PVP-COOH at room temperature.The structure of the s-PLLA-PVP copolymers was confirmed with FT-IR,1H NMR,GPC.The crystallization property and thermal properties of s-PLLA-PVP were characterized by XRD,TGA and DSC. The contact angle was useful for evaluating the surface hydrophilicity of s-PLLA-PVP copolymers.The results indicated that the thermal stability of s-PLLA-PVP was improved with the increasing of molecular weights of s-PLLA.The crystallinity of s-PLLA-PVP was decreased and the hydrophilicity was increased by adding PVP.