通过消除分子链中的缺陷结构提高PMMA树脂的热稳定性和透光性

项目名称： 通过消除分子链中的缺陷结构提高PMMA树脂的热稳定性和透光性

项目编号： No.51273026

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 张会轩

作者单位： 长春工业大学

项目金额： 80万元

中文摘要： PMMA是透光性最好的聚合物，但热稳定性差，其原因是PMMA分子链中含有结构缺陷。例如：分子链的不饱和端基、单体单元之间的头头链接、微量氧进入聚合物主链等等。如果不在聚合过程中对这些缺陷加以控制，得到的PMMA树脂在成型加工过程中会发生热分解，损害透光性和力学性能，甚至导致产品变黄。虽然这些结构缺陷的含量极微，但对产品性能却起着决定性作用。这些结构缺陷的确切化学结构是什么？如何产生的？怎样去消除？一直是工业界和学术界关注的问题，至今仍然没有完全搞清楚。本项目将要研究聚合工艺、聚合物链的结构缺陷、终端产品性能之间的关系。本项目将通过对MMA高温连续本体聚合的工艺创新，实现对PMMA分子链结构的控制，防止分子链内结构缺陷的形成，达到提高PMMA树脂产品热稳定性和透光性的目的。本项目还将探索用共聚单体GMA与聚合体系中的链转移剂硫醇反应，原位生成硫醚类大分子抗氧剂，彻底根治PMMA树脂变黄。

中文关键词： 聚甲基丙烯酸甲酯；连续本体聚合；热稳定性；透光率；弱键

英文摘要： Poly(methyl methacrylate) (PMMA) is a transparent thermoplastic with highest visible light transmittance, widely used in many sophisticated applications， and has become an important product for the manufactures of thermoplastics. Unfortunately, For a long time, foreign company dominant the PMMA resin market. Our country does not have the technology to produce PMMA. The polymerization of methyl methacrylate is probably the best described polymerization reaction in polymer science. However, the PMMA polymer is not as simple as we expected, the polymer chain of PMMA contain some weak linkages, such as: head-to-head bonds that form by combination termination of two active polymer chains; unsaturated end groups that form by disproportionation termination of two active polymer chains; and the trace amount of leaking oxygen copolymerize into the polymer main chain. What is the exact structure of these weak linkages? How was it formed? How to eliminate it? All these problems have not competely solved yet. It was, therefore, necessary to study the relation of polymerization, weak linkage in the polymer chain, and the properties of end products. In this study, novel polymerization recipe will be designed to prevent the formation of weak linkage, and as a results, it will improve the transmittance and the thermal-stability

英文关键词： poly(methyl methacrylate_；continuous bulk polymerization；thermal stability；light transmittance；weaklinkage