氯化镁/甘油改性羧甲基淀粉/聚乙烯醇共混材料的结构与性能

为获得改性淀粉/聚乙烯醇(PVA)共混材料的结构与性能特征,以氯化镁/甘油为复配改性剂,采用溶液成膜方法制备了羧甲基淀粉(CMS)/PVA,研究了CMS/PVA复合膜的红外吸收特性、结晶性能、微观形貌、热性能、力学性能及生物降解性。研究结果表明,氯化镁和甘油可与CMS/PVA产生电子相互作用和氢键作用,阻碍CMS/PVA分子链的规整排列,提高羧甲基淀粉与PVA的相容性,降低CMS/PVA的结晶度和热稳定性。氯化镁/甘油复配改性剂对CMS/PVA的力学性能影响显著,可使CMS/PVA断裂伸长率和拉伸强度提高。氯化镁/甘油可促进CMS/PVA的降解,增加氯化镁/甘油复配改性剂中氯化镁的含量可提高复合膜的降解率。

Structure and Properties of Carboxymethyl Starch/Poly(vinyl alcohol) Films Modified with Magnnesium Chloride and Glycerol

Carboxymethyl starch (CMS)/poly (vinyl alcohol)(PVA) films were prepared by solution method using magnesium chloride hexahydrate (MgCl2 · 6H2O) and glycerol as complex modifiers.The interaction between the complex modifiers and CMS/PVA was analysed by Fourier transform infrared spectroscopy (FT-IR).The influences of the complex modifiers on the crystalline and thermal properties were investigated by X-ray diffraction(XRD) and thermogravimetric analysis(TGA).The biodegradability of CMS/PVA films with the content of MgCl2· 6H2O/glycerol was studied.It is found that MgCl2· 6H2O and glycerol could form electron effect and hydrogen bonding with CMS/PVA chains respectively blocking the regular arrangement of molecular chains,which improve the compatibility of carboxymethyl starch and PVA and decrease the crystallinity of CMS/PVA films.The TGA results show that the thermal stability of CMS/PVA films decreases with the addition of MgCl2· 6H2O and glycerol.The obtained CMS/PVA films show higher tensile strength and elongation at break after modification.MgCl2· 6H2O/glycerol contributes to microbial strain entering into decomposition points so as to improve the degradation rate of CMS/PVA films.