THERMAL PERFORMANCE OF CYANATE FUNCTIONAL THERMOSETTING RESINS.

Abstract

Polycyanurate thermoset plastics prepared by the cyclotrimerization of aryl dicyanates are compared to toughened bismaleimides and a tetrafunctional epoxy for both short and long term aspects of thermal performance. Oligomers of three aryl dicyanates, including a flame retardant sulfur-linked bisphenol derivative, developed superior cured-state properties when catalyzed with specific metal acetylacetonates and phenolic catalysts. Performance exceeded that of the BMI and epoxy reference materials with respect to the onset of rapid degradation in air (approximately 400 degree C), moisture absorption in boiling water (1-3%), peel strength to 250 degree C, and impact resistance. Performance was intermediate with respect to modulus retention (wet and dry), and inferior to BMI's for long term stability in air at temperatures exceeding 200 degree C.