温度和湿度对PBAT/PLA薄膜性能变化的影响

Effect of Temperature and Humidity on the Properties of PBAT/PLA Films

为研究温度和湿度对聚对二苯甲酸-己二酸丁二醇酯(PBAT)/聚乳酸(PLA)薄膜的物理力学性能、热力学性能以及分子量变化的影响;采用恒温恒湿试验箱、拉力试验机、高温凝胶色谱仪、热机械分析仪、傅里叶红外光谱仪等设备分析分别在25℃/50%湿度(RH)、25℃/80%RH、50℃/80%RH三种环境条件下放置98 d的PBAT/PLA薄膜的性能。结果表明,在高温和高湿条件下,PBAT/PLA薄膜的拉伸强度、断裂伸长率、储能模量、分子量受到显著影响,在50℃/80%RH条件下处理98 d后,纵向拉伸强度保持率为38.4%,断裂伸长率保持率为5.3%,横向拉伸强度保持率为41.0%,断裂伸长率保持率0.8%;数均分子量下降了52%,重均分子量下降了76%,储能模量下降了40%。本研究工作对全生物降解塑料膜、袋的预期使用寿命具有一定的指导意义。

In order to investigate the effects of temperature and humidity on the physical mechanical properties,thermodynamic properties and molecular weight changes of poly(p-dibenzoate)-butylene glycol adipate(PBAT)/polylactic acid(PLA)films,the performance of PBAT/PLA films,which were left for 98 d at 25℃/50%RH,25℃/80%RH and 50℃/80%RH was analyzed by using constant temperature and humidity test chamber,tensile testing machine,high temperature gel permeation chromatography,dynamic mechanical and Fourier infrared spectrometers.The results show that under high temperature and high humidity conditions,the tensile strength,elongation at break,energy storage modulus and molecular weight of PBAT/PLA film have significant effects.After 98 d at 50℃/80%RH for,the retention rate of longitudinal tensile strength is 38.4%,the retention rate of elongation at break is 5.3%,the retention rate of transverse tensile strength is 41.0%,and the retention rate of elongation at break is 0.8%.The number-average molecular mass decreases by 52%,the mass-average molecular mass decreases by 76%,and the energy storage modulus decreases by 40%.This study has certain guiding significance for the expected service life of the whole biodegradable films or bags.