Correlations of Norbornenyl Crosslinked Polyimide Resin Structures with Resin Thermo-Oxidative Stability, Resin Glass Transition Temperature and Composite Initial Mechanical Properties.
Abstract
PMR (polymerization of monomeric reactants) methodology was used to prepare seventy different polyimide oligomeric resins and thirty different unidirectional graphite fiber/polyimide composites. Monomeric composition as well as chain length between sites of crosslinks were varied to examine their effects on resin thermo-oxidative stability and glss transition temperature (Tg) of the cured/postcured resins. A linear correlation of decreasing 316 C resin weight loss/surface area versus (a) decreasing aliphatic content or (b) increasing benzylic/aliphatic stoichiometry ratio over a wide range of resin compositions was observed. An attempt was made to correlate Tg with initial composite mechanical properties (flexural strength and interlaminar shear strength). However, the scatter in mechanical strength data prevented obtaining a clear correlation. Instead, only a range of composite mechanical properties was obtained at 25, 288 and 316 C. Keywords: Glass transition temperature; Composite mechanical properties; Polyimide; Thermo-oxidative stability; Graphite fiber composites.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1988
- Accession Number
- ADA193313
Entities
People
- William B. Alston
Organizations
- Glenn Research Center