Crosslinked polyimide foams derived from poly(imide-propylene oxide) copolymers
Crosslinked polyimide foams derived from poly(imide-propylene oxide) copolymers
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DOI：
10.1002/macp.1997.021980227
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发表时间：
1997-02-01
影响因子：
2.5
通讯作者：
McGrath, JG
中科院分区：
文献类型：
--
作者：
Hedrick, JL;Carter, K;McGrath, JG
一种新的路线，用于高玻璃化转变温度，热稳定的聚合物泡沫的合成已被开发，使用组成不对称的微相分离的嵌段共聚物，其中次要组分（聚（环氧丙烷））是热不稳定的和主要组分（聚酰亚胺）是热稳定的。次要组分在加热时分解成低分子量物质，并且分解产物扩散出膜，留下嵌入热稳定组分的基质中的孔。在这项研究中，聚酰亚胺块与乙炔基官能团交联，以获得稳定的多孔结构。通过热重分析、动态力学分析和热机械分析研究了嵌段共聚物中环氧丙烷的分解。需要温和的条件以避免环氧丙烷的快速解聚和聚酰亚胺基质的塑化。泡沫显示出直径高达微米尺寸的孔径以及预期的质量密度降低。
A new route for the synthesis of high glass transition temperature, thermally stable polymer foams has been developed, using compositionally asymmetric microphase-separated block copolymers where the minor component (poly(propylene oxide)) is thermally labile and the major component (polyimide) is thermally stable. The minor component decomposes to low molecular weight species upon heating, and the decomposition products diffuse out of the film, leaving behind pores embedded in a matrix of the thermally stable component. In this study, the polyimide block was crosslinked with ethynyl functionalities to obtain a stable porous structure. The decomposition of the propylene oxide in the block copolymer was studied by thermogravimetric, dynamic mechanical and thermomechanical analyses. Mild conditions were required to avoid rapid depolymerization of the propylene oxide and plasticization of the polyimide matrix. The foams showed pore sizes with diameters up to a micrometer in size as well as the expected reduction in the mass density.