CMC/PE膜的制备及其保鲜和降解性能的研究

摘  要

具有优良保鲜性能的可降解膜是果蔬保鲜包装领域需求越来越大的一种功能性薄膜。本文以PE为基材，选择羧甲基纤维素钠（CMC）为填充剂，针对改善薄膜的透气性、透湿性和降解性，制备了不同添加量的CMC填充膜。根据薄膜的拉伸强度、断裂伸长率、吸水性和透气性，分析不同添加量的CMC对薄膜基本性能的影响。利用所制薄膜对平菇进行保鲜实验，通过测定平菇的感官评分、失重率和好菌率，研究不同添加量的CMC填充膜对平菇保鲜效果的影响。在降解实验中，根据薄膜的失重率和力学性能的改变，研究CMC填充膜的降解性能。
结果表明，以LDPE与LLDPE共混树脂（4:1）为基材，树脂总量(g)与二甲苯用量(ml)比例为1:50所制薄膜的综合性能较好；随着CMC添加量的增加，薄膜的拉伸强度和断裂伸长率有一定的降低，薄膜的吸水率和水蒸气透过率较空白膜有较大的改善；与对照组和空白膜保鲜效果相比，CMC填充膜有优异的保鲜性能，CMC添加量为15%的薄膜对平菇的保鲜效果最好；CMC的填充改善了薄膜的降解性能，CMC填充量越大，薄膜降解效果越明显。

关键词：聚乙烯，保鲜，降解，CMC，平菇
 
ABSTRACT

With excellent capability of fresh-keeping and degradation, the functional film is growing demanded in the field of packaging fresh fruits and vegetables. In this paper, PE material was used as matrix resin and the CMC as filler to improve the gas and vapor permeation and degradability of film，and many films were prepared with different content of CMC. According to the tensile strength, elongation at break, water absorption and water vapor transmission of film, the effect of different CMC content on the basic properties of films were analyzed; films were used to package Pleurotus ostreatus and examine fresh-keeping performance; through film degradation experiments, weightlessness rate and mechanical properties changes of the films were determined to research the degradability of CMC/ PE film.
The results showed that LDPE/LLDPE(4:1), resin total/ amount of xylene(1:50) could make better comprehensive films. As the amount of CMC increased, the tensile strength and the elongation at break of the films had reduced gradually, but the capability of water absorption and water vapor transmission had increased. CMC/PE films had excellent capability of keeping-fresh, when the amount of CMC added to 15%, the film could keep the Pleurotus ostreatus fresh. CMC/PE film could accelerate films’ degradation. It was shown that CMC/PE film had good degradability, and the degradation degree of film was more than that of pure PE film.

Keywords: PE, degradation, fresh-keeping, CMC, Pleurotus ostreatus
 

*若需了解更多与协助请咨询↓→[电脑QQ][手机QQ]【数据协助】