相对分子质量可控聚酰亚胺薄膜的聚集态结构  

Aggregation State of Polyimide Films Prepared from Molecular Weight Controlled Poly (amic acid) Resins

作　　者：袁莉莉[1] 崔超[2] 周典瑞 洪伟杰 王志媛[1] 杨士勇[1] Lili Yuan;Chao Cui;Dianrui Zhou;Weijie Hong;Zhiyuan Wang;Shiyong Yang(Laboratory of Advanced PoLymrr Materials,Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China;Institute of Materials & Processing Technology,Beijing 100076,China)

机构地区：[1]中国科学院化学研究所高技术材料实验室,北京100190 [2]航天材料及工艺研究所,北京100076

出　　处：《高分子材料科学与工程》2019年第7期31-37,43,共8页Polymer Materials Science & Engineering

基　　金：国家重点基础研究发展计划(“973”计划)资助(2014CB643604);国家自然科学基金青年基金资助项目(51803222)

摘　　要：将芳香族二酐(3,3′,4,4′-联苯四酸二酐,BPDA)和芳香族二胺(4,4′-二氨基二苯醚,ODA)在反应性双官能团封端剂(4-苯乙炔苯酐,PEPA)的存在下于极性非质子溶剂中通过缩聚反应制备相对分子质量可控的聚酰胺酸(PAA)树脂溶液,然后将高固含量、低黏度的PAA树脂流延涂敷在玻璃板上,在加热条件下获得聚酰亚胺(PI)薄膜。采用X射线衍射和动态力学热分析手段对PI薄膜的聚集态结构进行了研究,发现热亚胺化反应引发的树脂主链结构的取向大致与高温下链段解取向相抵消,但反应性苯乙炔封端基团的扩链反应约束了醚桥键和联苯键的构型,构成链段规整有序排列的若干个沿面内取向的微晶态区,致使晶体结构快速增长,增强增韧PI薄膜。The molecular-weight-controlled poly(amic acid)(PAA)resin functionalized with phenylethynyl end-groups were prepared via the polycondensation of 3,3′,4,4′-biphenyltetra-carboxylic dianhydride(BPDA),4,4′-oxydianiline(ODA)and 4-phenylethynyl phthalic anhydride(PEPA)served as molecular-weight-controlling and reactive end-capping agent.The PAA resin with relatively high concentration were employed to form the PAA film by solution-cast method,which was then thermally converted to the fully-cured polyimide(PI)film.The aggregation state of the PI film with flexible main-chain structure and relatively high molecular weights was investigated systematically by XRD and dynamic thermo-mechanical analysis.It is found that the degree of polymer chain order caused by thermal imidization counteracts that of chain segment disorientation induced by elevated temperature.The covalent incorporation of chain-extension structures in the backbones,induced by thermal curing of phenylethynyl groups,might slightly constrain the configuration of ether and biphenyl linkages,and facilitate ordered in-plane oriented micro-regions,thereby strengthening and toughening the PI film.

关 键 词：聚酰亚胺 相对分子质量可控 聚酰胺酸 聚集态结构 

分 类 号：TB383.2[一般工业技术—材料科学与工程]