Cure Characteristics of Tricyanate Ester High - Temperature Composite Resins

Highly aromatic tricyanate ester resins exhibit glass transition temperatures well in excess of 350 degrees Celsius when thermally cured to full conversion. In many cases, though, complete conversion is difficult to achieve in practice due to the highly rigid nature of the molecules. A thorough understanding of the cure process is thus important for realizing the full potential of these materials. In order to characterize the cure of these systems completely, measurements of cure kinetics were undertaken using both isothermal and non-isothermal DSC, and compared to measures of conversion obtained through IR spectroscopy and thermomechanical analysis. These measurements were performed on Primaset PT-30 (a commercially available resin), as well as a newly synthesized tricyanate with enhanced molecular chain flexibility. The effect of catalytic impurities on the cure kinetics and extent of cure was also examined. The more flexible tricyanate showed a decrease in activation energy as well as increased extent of network formation after cure temperatures ranging from 210 to 290 degrees Celsius. Although the Tg at full conversion of the flexible tricyanate was lower than that of PT-30, the increased extent of network formation enabled the flexible system to achieve Tg values nearly as high or higher than the corresponding values for PT-30 under identical cure conditions.