预糊化对挤压吹塑制备淀粉/PVA纳米复合膜性能的影响

为了获得高性能的淀粉基复合膜,选取羟丙基交联淀粉(HP)和2种预糊化羟丙基交联淀粉(PC、PE)为成膜基材,分别与2种聚合度的PVA(1 700、2 400)复合,添加有机改性蒙脱土为增强剂,采用挤压吹塑法制备了淀粉/PVA纳米复合膜。结果表明:PC/PVA、PE/PVA复合膜表面不存在淀粉颗粒碎片,HP/PVA复合膜表面分布着未糊化的淀粉颗粒;同种淀粉和高聚合度的PVA之间,界面亲合力更强,相容性更好,形成的复合膜力学性能较好,疏水性能更强;预糊化淀粉有利于良好、有序插层结构的形成,与PVA分子之间联结更紧密,阻碍了水分子的吸附和透过。

Effects of pregelatinization on properties of starch/PVA nanocomposite films prepared by extrusion blowing

Hydroxypropyl distarch phosphate (HP) and two pregelatinized hydroxypropyl distarch phosphate (PC, PE) compounded with two kinds of PVA (degree of polymerization 1 700, 2 400), enhanced with organically modified montmorillonite were prepared by extrusion blowing to obtain high performance starch-based films. The result showed that, there was no starch granule fragments on the surface of PC/PVA or PE/PVA film, while ungelatinized starch granules were exhibited on the surface of HP/PVA film. The same kind of starch had stronger interface affinity and better compatibility with higher degree of polymerization of PVA, and the film showed better mechanical and hydrophobic properties. Pregelatinized starch facilitated the formation of well and ordered intercalation structure. And pregelatinized starch linked with PVA more closely, which hindered the adsorption and transmission of water molecules.