Toughening of a bisnadimide thermosetting resin by blending with initially soluble or particulate linear polyimides
- CNRS, Varnaison (France); and others
Improvement of fracture toughness without reduction of thermomechanical properties is a crucial question for the development of composite polymer matrixes. A general mean of meeting this goal in the field of high-temperature thermosets is to introduce a tough minor thermoplastic constituent. Within this scope, our approach is based on the use of linear polyimides exhibiting glass transition temperatures higher than those of the host crosslinked structures. This has been investigated to modify a bisnadimide thermosetting resin (bulk fracture energy G{sub 1}C {approx} 200 J/m{sup 2}) following two different ways. The first one involves a high molecular weight cardo-fluoro polyimide which is miscible with the basic thermoset in solution, but produces a phase-separated blend after cure. The second one consists in dispersing preformed polyimide particles (average diameter < 10 {mu}m) into the starting resin. Depending on the powder preparation method, the polyimide particles show amorphous or semi-crystalline morphologies but they remain fully immiscible with the polynadimide network. A comparative study of the blend properties points out a greater increase in fracture energy with the cardo-fluoropolyimide (G{sub 1}C = 1100 J/m{sup 2} with 22 wt %) whereas the dispersed particulate polyimide brings about a good balance between processing and mechanical performances.
- OSTI ID:
- 127063
- Report Number(s):
- CONF-950402-; TRN: 95:006086-1157
- Resource Relation:
- Conference: 209. American Chemical Society (ACS) national meeting, Anaheim, CA (United States), 2-6 Apr 1995; Other Information: PBD: 1995; Related Information: Is Part Of 209th ACS national meeting; PB: 2088 p.
- Country of Publication:
- United States
- Language:
- English
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