物理老化过程对聚乳酸阻隔性能的影响  

Effect of Physical Aging on Barrier Properties of Poly(L-Lactide)

作　　者：于振菲 王羽[1] 梁晓红[1] 孙文秀[1] 靳烨[1] 董同力嘎 

机构地区：[1]内蒙古农业大学食品科学与工程学院,内蒙古呼和浩特010018

出　　处：《高分子材料科学与工程》2015年第9期82-86,共5页Polymer Materials Science & Engineering

基　　金：国家自然科学基金资助项目(51163010);内蒙古草原英才工程(2011)

摘　　要：研究了不同旋光度的聚乳酸(PLLA)的阻隔性能随物理老化过程的变化情况,采用差示扫描量热分析仪、透氧仪和透湿仪对PLLA薄膜的热学性能和阻隔性能进行了研究。差示扫描量热分析结果表明,随着老化时间延长,PLLA薄膜的玻璃化转变温度(Tg)增高,焓松弛面积逐渐增大,而结晶度(Xc)没有发生变化。物理老化对PLLA薄膜的阻隔能力十分敏感,物理老化时间延长有效地提高了PLLA薄膜的阻隔性能。氧气透过系数(OP)和水蒸气透过系数(WVP)的变化速率是不均一的:在Ta<48h时,气体透过系数曲线呈急剧下降趋势;在Ta>48h时,曲线的斜率逐渐趋于平缓。而且D-乳酸含量相对较低的PLLA表现出较高的阻隔性能。In order to study the barrier property of PLLA films with different physical aging time. Meanwhile the effects of rotation on the barrier properties were also discussed in detail. The thermal behavior and barrier property of PLLA films were investigated by differential scanning calorimetry （DSC）, oxygen and moisture permeable instrument, respectively. The DSC results show that the glass-transition temperature （Tg） is move to high temperature and the enthalpy relaxation （AHr） increases with physical aging time, the crystallinity almost does not change in the physical aging process. The barrier property is sensitive to physical aging. The barrier properties of PLLA films are improved with physical aging time. The magnitude change of oxygen permeability （OP） and water vapor permeability （WVP） are not uniformity and become every smaller with physical aging time. In less than 48 h, the curves of gas permeability coefficient are sharp declined, and with the further aging （ 〉48 h）, the slope of curves is gradually gentled, indicating that the changes of chains relaxation rate caused by physical aging is not an average amount. The PLLA films with relatively lower contents of poly （D-lactic acid） have better oxygen and water barrier properties.

关 键 词：聚乳酸 物理老化 焓松弛 阻隔性能 

分 类 号：TQ317.6[化学工程—高聚物工业]