高透氧性纤维素包装膜的制备

鲜果蔬保鲜包装中包装膜的阻隔性能对于果蔬的保鲜具有重要影响,本研究利用不同种类的凝固浴制备LiCl/DMAc工艺再生纤维素包装膜,并考察了甲醇、乙醇、异丙醇、LiC l/DMAc和去离子水对纤维素包装膜的断面结构、表面结构、透氧和透湿性能以及机械性能的影响。结果表明,使用醇类凝固浴制备的纤维素包装膜的断面呈松散结构,尤其是以乙醇凝固浴制备的包装膜出现了指状孔;包装膜的透氧性能明显提高,乙醇凝固浴制备的纤维素包装膜的透氧系数为15%LiCl/DMAc凝固浴制备的纤维素包装膜的50倍,并且其机械性能达到12.7Mpa,可以满足日常包装性能要求。

Preparation of Cellulose Packaging Films with High Oxygen Permeability

The barrier properties of the cellulose packaging films have great influence on the fruits and vegetables fresh - keeping packaging. In this study, the porous cellulose packaging films were prepared with natural broad - leaved pulp and LiC1/DMAc by different types of coagulation baths. The effects of methanol, ethanol, isopropanol, LiCI/DMAc and deion- ized water on the physical structures, oxygen and water vapor permeabilities and mechanical properites of the films were measured. Based on the SEM observation, the cross section structure was loose with the alcohol coagulations, especially the films with ethanol coagulation showed dactylopores. It was also found that the oxygen permeability has been obviously im- proved with the ethanol coagulation bath and is as 50 times as the film which prepared with 15% LiC1/DMAc coagulation bath. The porous cellulose packaging films had better mechnical properties with up to 12.7Mpa, which would satisfy the us- age in packaging.