Abstract: The terminal carboxyl group of polylactic acid copolymer P (LA/SA) was synthesized with lactide as raw material,stannous caprylate as the catalyst and succinic anhydride as modifier by direct melt polycondensation,and under the condition of 150℃ and 0.098MPa (LA/SA). The polyesteramide (PEA) was synthesized using 2,2-(1,3-phenylene)-bis(2-oxazoline) (1,3-PBO) chain the terminal carboxyl group of polylactic acid copolymer with the n(lactide)/n(1,3-PBO) is 1/2.4 and the reaction time of 12h. Finally,Kaolin and PEA melting compound was modified under stress conditions at 150℃. The structure were characterized by FTIR and the properties were investigated by GPC,FTIR, ¹H NMR,DSC,SEM. The result showed that the relative molecular weight of the chain extender product PEA increased significantly compared with P (LA/SA),and the heavy molecular weight was up to 240000. Its glass transition temperature is also higher than that of PLA and P (LA/SA). The thermal stability of the composite material is improved and the crystallinity is reduced after being modified.

Key words: poly(D,L-lactide), 2,2'-bis( 2-oxazoline), chain extending, Kaolin, composites

摘要： 以丙交酯为原料、辛酸亚锡为催化剂、丁二酸酐为改性剂,采用梯度升温法,在150℃、0.098MPa条件下采用直接熔融缩聚法合成端羧基聚乳酸共聚物P(LA/SA),接着用2,2-(1,3-亚苯基)-二 唑啉(1,3-PBO)对其进行扩链,按n(丙交酯)/n(1,3-PBO)= 1/2.4加入1,3-PBO,反应1h制得聚酰胺酯(PEA),最后将高岭土与PEA在150℃、减压条件下熔融复合改性。采用GPC、FTIR、¹H NMR、DSC、SEM等手段对聚合物的结构进行表征和性能测试,结果表明,与P(LA/SA) 相比,扩链产物PEA相对分子质量大幅度提高,重均相对分子质量高达24万,玻璃化转变温度T_g高于PLA和P(LA/SA),改性后复合材料的热稳定性能提高,结晶度降低。

关键词: 聚乳酸, 二 唑啉, 扩链法, 高岭土, 复合材料