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Crosslinked polyimide foams derived from poly(imidepropylene oxide) copolymers
Author(s) -
Hedrick J. L.,
Carter K.,
Sanchez M.,
Di Pietro R.,
Swanson S.,
Jayaraman S.,
McGrath J. G.
Publication year - 1997
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.1997.021980227
Subject(s) - polyimide , materials science , copolymer , propylene oxide , depolymerization , oxide , thermogravimetric analysis , polymer chemistry , glass transition , polymer , chemical engineering , decomposition , composite material , ethylene oxide , chemistry , organic chemistry , layer (electronics) , engineering , metallurgy
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.