Exploratory Development of High Temperature Resins for Structural Laminates and Adhesives.
Abstract
The polyimidazoquinazoline, PIQ, heterocyclic resin system has been investigated as a high-temperature support resin, and to a limited extent, as a structural adhesive, in several trifunctional and difunctional modifications. Marked improvements in ring-closure efficiency, providing an integral cyclized structure, have been realized through the use of a streamlined cure-postcure schedule which has included a short-term final exposure to temperatures exceeding 90 F (the approximately glass-transition temperature of the system) preferably at 975 F. Low-void, high-perfection laminates have been fabricated with Modmor-II unidirectional reinforcement whose flexural properties equal or exceed the levels of capability of conventional high-performance support resin systems. Further, when a 100% trifunctionally-curing system was used (AF-R-530 triazine centered crosslink), in conjunction with the streamline cure-postcure, a singular level of high-temperature, thermomechanical performance has been realized in Modmor-II-unidirectionally reinforced laminates. For example, a maximum room temperature flexural strength/modulus level of 281,500 psi/17.2 x 10 to the 6th power psi has been realized, with retention of 100% and 84% of initial strength after 50 hr and 100 hr aging, respectively, at 700 F tested at 700 F. This composite lost only 6.5% weight during the 100-hr exposure. A similar laminate retained 61% of its orginial flexural strength after 5 hr at 800 F (tested at 800 F), and 39% of same after 1 hr at 1000 F (tested at 1000 F). 2912
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1972
- Accession Number
- AD0903797
Entities
People
- Beatrix Y. Sanders
- Robert J. Milligan
- Walter P. Fitzgerald Jr.