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Kevlar 49 composite performance: Dependence on thermoset resin microstructure

✍ Scribed by D. C. Timm; A. J. Ayorinde; C. H. Lee; L. F. Steele; N. C. Plass


Publisher
Society for Plastic Engineers
Year
1984
Tongue
English
Weight
519 KB
Volume
24
Category
Article
ISSN
0032-3888

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✦ Synopsis


Abstract

Molecular structures for cured, thermoset resins have been examined by analyses of resin extracts by gel permeation chromatography. Numerical interpretation of leached oligomeric fractions coupled with kinetic reaction theory yields microscopic estimates of the network's structure, including crosslink average molecular weight. Leached monomeric fractions describe extent of cure. Analyses of test data incorporate irreversible, mechanical deformations for neat resin castings and for filament wound, Kevlar 49 composites. Heat distortion temperatures correlate with crosslink architecture. Short beam shear strength data for naval ordinance laboratory rings and pressure vessel burst performance are examined in terms of the resin's molecular structure. Variations in resin cure observed by positive feedback via chromatography indicate fluctuations in extent of crosslink development. Test specimen performance correlates with these microscopic, molecular distributions. Resin applications include filament wound composites for the aerospace industry, anhydride cured epoxies, and amine cured epoxies. The former resin is an elastic body at ambient test conditions. A third resin, a crosslinked resin of 1,2 polybutadiene/t‐butylstyrene, is in final developmental stages and may exhibit a higher degree of viscoelastic behavior.