基于原子力显微镜的聚乳酸降解研究  

Degradation of Polylactic Acid Based on the Atomic Force Microscope

作　　者：高阿红 成博 刘峰 王俊元[1] 孟荣杰 GAO A-hong;CHENG Bo;LIU Feng;WANG Jun-yuan;MENG Rong-jie(School of Mechanical Engineering,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学机械工程学院,太原030051

出　　处：《包装工程》2021年第7期69-75,共7页Packaging Engineering

基　　金：国家自然科学基金(21604074)。

摘　　要：目的为了探究可降解聚乳酸在单分子层次的降解性能及其降解速率,使聚乳酸材料更好地应用于生物医学领域。方法采用原子力显微镜在纳米层次上分别研究单个聚乳酸链在水以及酸、碱性溶液中的单分子力谱。结果通过对其单链拉伸结果进行分析,发现单个聚乳酸分子链在纯水中短时间内发生水解断链的概率较小,可以保持其原有的长链和本征弹性,而在酸、碱性环境中则会在短时间内发生酸、碱微环境导致的加速水解行为,从而使长链聚乳酸分子较短时间内水解成为短链聚乳酸分子。通过对宏观颗粒状聚乳酸材料降解质量损失的分析,也说明酸、碱微环境会加速聚乳酸水解过程。结论从单分子层次上进一步证明了水解过程中发生微环境的改变对聚乳酸降解速度的改变起着重要作用。The propose is to explore the degradability and degradation rate of single polylactic acid chain on the single molecule level and make polylactic acid materials better used in the field of biomedicine.In this paper,by using atomic force microscopy,the single-molecule force spectroscopy of one single polylactic acid chain in water,acid and alkaline solutions are studied at the nanoscale.Based on the analysis of the single chain stretching results,it is found that the single polylactic acid chain is less likely to be hydrolyzed and broken in pure water in a short time,and but also maintain its original long chain and intrinsic elasticity.However,when it is in acid or alkaline environments,the accelerated hydrolysis behavior caused by acid or alkali environment will take place in a short time,which makes the long polylactic acid chain hydrolyze into many short polylactic acid chain fragments in a short time.It is proves that the change of the micro-environment play an important role in the accelerating hydrolysis process of polylactic acid chains on the single molecule level.

关 键 词：聚乳酸 水解 单分子力谱 降解速度 

分 类 号：TS206.4[轻工技术与工程—食品科学]