淀粉/聚乳酸共混材料的增容改性研究

STUDY ON COMPATIBILIZATION OF STARCH/POLYLACTIC ACID BLEND

实验以γ-氨基丙基三乙氧基硅烷(KH550)、钛酸四丁酯(TBOT)和甲苯二异氰酸酯(TDI)为偶联剂,以溶剂挥发法制备淀粉/聚乳酸共混材料。考察了材料的相容性、吸水性以及降解性,利用IR、DSC和SEM等对材料表面结构进行表征。实验结果表明,加入共聚物的淀粉/聚乳酸共混体系的相容性较好,以KH550为偶联剂的材料在酸碱缓冲液中的稳定性最好,pH值随时间变化最小,264 h后在酸液中为0.42,在碱液中的为1.10;以KH550为偶联剂的吸水率最低,为18.2%。淀粉聚乳酸接枝共聚物改善了材料的相容性,提高了共混体系的耐水性和耐酸碱性。

Compatible function of starch-polylactic acid graft copolymer on starch/PLA blend, with KH550, tetrabutyl titanate or TDI as coupling agents, was studied. The starch/PLA blend material was prepared by in-liquid drying. Properties of the starch/PLA blend, including compatibility, water absorbency and degradability, were studied. The products were characterized by infrared spectrosco- py, scanning electron microscopy and differential thermal analysis. The results showed that KH550 was the best in improving the compatibility of stareh/PLA blend, pH value change rate（ApH） of the biodegradable fluid of the starch/PLA blend material with KH550 after 264 hours was 0.42 in alkali liquor, and 1.10 in acid liquor, respectively, with which the stability of the blend was the best. Also the graft eopolymer improved the compatibility of the blend appreciably, and water absorption rate of the blend with KH550 was the lowest, 18.2%.