Title page for ETD etd-05222007-091419
|Type of Document
||Synthesis and characterization of high Tg nanofoams based on pyromellitic dianhydride and 1,1-bis(4-aminophenyl)-1-phenyl-2,2,2-trifluoroethane polyimide block and graft copolymers
|McGrath, James E.
|Gibson, Harry W.
|Goldfarb, Ivan J.
|Marand, Hervé L.
|Riffle, Judy S.
- polymer applicatioons in electronics
- polymer properties
|Date of Defense
Thermally stable polyimide block and graft copolymers with labile con1ponents
(especially polypropylene oxide), have been prepared and investigated as low dielectric
materials that afford desirable thermal, mechanical and electrical properties. Polyimide
nanofoams based upon the controlled pyrolysis of the labile component were prepared.
The methodology for producing the nanofoams was to first spin cast well-designed
microphase separated graft or block copolymer solutions comprised of the thermally stable
1, I-Bis( 4-aminophenyl)-1-phenyl-2,2,2-trifluoroethane (3FDA)/pyromellitic dianhydride
(PMDA) based polyimide main chain and polypropylene oxide based thermally labile graft
of block copolymers. The thermally stable material was designed to be the continuous
phase, and the unstable moiety served as the dispersed phase so that closed cell structures
could be obtained. Upon thermal treatment under inert atmosphere, the materials can be
spun cast and cured in place, if so desired. However, if the polymers are exposed to the
oxygen atmosphere, the unstable component can be selectively degraded, generating
micropores that are related to the size of the initial microphase separated copolymer
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