天然抗氧化羟丙基甲基纤维素水溶性包装薄膜

Water-Soluble Natural Antioxidant Hydroxypropyl Methyl Cellulose-Based Packaging Film

将竹叶抗氧化剂(AOB)添加到羟丙基甲基纤维素(HPMC)制膜液中,采用流延法制得具有抗氧化性能的AOB/HPMC复合水溶性包装薄膜。并通过红外吸收光谱、X射线衍射、热重分析等对复合薄膜的官能团变化、结晶情况等进行了表征,测定了样品薄膜的透光率和雾度,利用DPPH自由基清除实验分析了薄膜的抗氧化性能。研究了AOB的添加量对复合包装薄膜的抗氧化性能、水溶性、力学性能和光学性能的影响。实验结果表明:AOB的添加没有破坏HPMC本身的基团,仅扰乱了分子链的排列,导致AOB/HPMC复合薄膜的结晶度下降,热分解温度提高,热稳定性能加强,具有抗氧化性的功能特性;且随着AOB添加量的不断增加,复合水溶性包装薄膜的水溶性不断提高,力学性能和光学性能有所下降,但下降幅度不大,抗氧化性能先增大后降低,当AOB的添加质量分数为0.03%时,复合薄膜对DPPH自由基的清除率达最大值,为89.34%。

Antioxidant extracted from bamboo leaf was added into hydroxypropyl methyl cellulose(HPMC)solution to prepare packaging films by casting method.The transformation of chemical structure and crystallizationconditions of the film were characterized by FT-IR,X-ray and TG.The transmittance and haze of the sample filmwere measured,while oxidation resistance properties of the film with different AOB contents were analyzed by theexperiment of scavenging DPPH radicals.The performance of the film including anti-oxidization,water-solubility,mechanical properties and optical properties with different contents of AOB additive were studied.The results showedthat the addition of AOB has not destroyed the chemical group of HPMC while only disturbed the arrangement of themolecular chains.The crystallinity of the AOB/HPMC composite film decreased,with the increase in temperatureof thermal decomposition and the enhancement of thermal stability,which indicated the anti-oxidation properties.Meanwhile,the water solubility of composite water-soluble packaging film increased with the increasing amount ofAOB,with the slight decrease in mechanical properties and optical properties,while the antioxidation increased firstlyand then decreased.When the addition amount of AOB was0.03wt%,the scavenging rate of DPPH free radicalsreached a maximum value of89.34%.