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Preparation and properties of rigid polyimide foams derived from dianhydride and isocyanate
Author(s) -
Yu Fei,
Wang Kai,
Liu XiaoYan,
Zhan MaoSheng
Publication year - 2012
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.38121
Subject(s) - polyimide , isocyanate , materials science , compressive strength , composite material , scanning electron microscope , thermal stability , polyurethane , polymer chemistry , chemical engineering , layer (electronics) , engineering
A series of rigid polyimide (PI) foams were synthesized via the reaction of a first solution with a second solution. The first solution was isocyanate‐terminated polyimide prepolymers; the second solution contained deionized water and surfactant. The effect of different water contents and isocyanate index on the structures and properties of rigid PI foams were investigated. The apparent density, hardness, compressive strength, and the 5% weight loss temperatures ( T 5% ) decreased with the increase of water content. With the increase of isocyanate index, the apparent density and the T 5% values decreased, whereas the glass transition temperatures ( T g ) increased and the hardness, compressive strength first increased and then decreased. The rigid PI foams composed of closed‐cells were confirmed by scanning electron microscopy. The maximum compressive strength of rigid PI foams prepared was up to 1.31 MPa. Moreover, excellent thermal stability was presented with the T 5% values were all above 360°C and the residual weights of the foams ( R w ) were more than 50% at 800°C. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013