Ca2+处理对低甲氧基果胶/壳聚糖复合膜结构与性能的影响研究

Study on the Preparation, Structure and Properties of Low Methoxy Pectin-Chitosan Composite Packaging Film

本文通过流延法制备了低甲氧基果胶/壳聚糖复合膜,并使用2%的CaCl2溶液对复合膜进行了后处理,探讨了Ca2+交联对复合膜结构和性能的影响。结果表明:Ca2+与果胶中-COOH结合交联,增强了分子链的刚性,促进复合膜形成致密的网络状结构,使复合膜的拉伸强度由4.29 MPa提高至7.84 MPa,同时膜的断裂伸长率由33.57%降低至30.00%;复合膜的吸水率和水蒸汽透过率分别降低了24.08%和13.04%;复合膜的热稳定性显著提高,熔点由37.8℃上升至43.3℃,起始氧化温度由164℃上升至172℃。

In this paper,low methoxy pectin/chitosan composite membranes were prepared throught tape casting method,and then the effects of Ca2+crosslink on the structure and properties of the composite membranes were investigated by treated the membranes with 2%CaCl2 solution.The results showed that Ca2+bonded to-COOH of pectin,which enhanced the rigidity of molecular chains and promoted the formation of dense network structure of the composite film.As a result,the tensile strength of the composite film increased from 4.29 MPa to 7.84 MPa,accompanied with the decreased elongation at break(from 33.57%to30.00%);In addition,the water absorption and vapor permeability decreased by 24.08%and 13.04%;Besides,the thermostability of the composite membranes was definitely improved,the melting point of membranes increased from 37.8℃to 43.3℃,while the initial oxidation temperature from 164℃to 172℃.