聚乳酸单轴拉伸膜的包装特性研究  

Packaging Characteristics of Uniaxially Stretched Poly( L-lactic acid) Film

作　　者：于振菲 吴佳鑫[1] 赵子龙[1] 王爽爽[1] 靳烨[1] 董同力嘎 

机构地区：[1]内蒙古农业大学,呼和浩特010018

出　　处：《包装工程》2014年第1期23-27,33,共6页Packaging Engineering

基　　金：国家自然科学基金(51163010);内蒙古草原英才科研基金(2011)

摘　　要：目的研究了不同拉伸比的PLLA薄膜的热学性能、阻隔性能和热收缩性能。方法采用双螺杆挤流延试验机单轴拉伸制备了不同拉伸比的PLLA热收缩膜和定向拉伸膜,采用差示扫描量热分析仪(DSC)、透湿仪和透氧仪对不同拉伸比的PLLA薄膜的热学性能和阻隔性能进行了评估,并对PLLA膜的热收缩性进行了测定。结果热收缩膜的拉伸比由1增大到6.5时,PLLA的结晶度由0.2%增加到41.8%,结晶速率明显提高,阻隔性得到了一定的改善。随着拉伸比例的增大,热收缩率随之增大。定向拉伸膜的结晶度得到了大幅度提高,其阻隔性也得到了改善,但不呈现热收缩性。结论通过单轴拉伸可以有效地提高PLLA薄膜的结晶速率和结晶度,经过中等拉伸比例的PLLA薄膜,其阻湿阻氧能力相对较强。Objective To study the thermal, barrier and thermal shrinkage properties of PLLA films with different draw ratios. Methods PLLA thermal shrinkage films with different draw ratios and uniaxially stretched PLLA films were prepared by a twin-screw extruder. Thermal shrinkage and barrier properties of the PLLA films with different draw ratios were measured by an DSC, a water vapor permeability tester and an oxygen permeability tester. Results The crystallinity of PLLA increased from 0.2% at ratio= 1 to 41.8% at ratio = 6.5, and the crystallization rate and crystallinity increased significantly. The barrier properties of PLLA were improved by the orientation and crystallization. The shrinkage films showed an excellent thermal shrinkage behavior, while the stretched films losted their thermal shrinkage. Conclusion Uniaxial stretching could effectively improve the crystallization rate and crystallinity of PLLA films. The moisture and oxygen barrier properties of the PLLA films are relatively good after medium stretching.

关 键 词：聚乳酸 阻隔性能 结晶性能 热收缩性能 

分 类 号：TB484.6[一般工业技术—包装工程]