Influence of phenoxy addition on the curing kinetics for uncatalyzed and catalized Cyanate ester resin

REMIRO , PEDRO; DE LA CABA, KORO; MONDRAGON, IÑAKI; RICCARDI, CARMEN

JOURNAL OF APPLIED POLYMER SCIENCE

JOHN WILEY & SONS INC

Año: 2010 vol. 118 p. 2869 - 2881

0021-8995

The curing behavior of the dicyanate esterof bisphenol-A (DCBA) modified with poly(hydroxy etherof bisphenol-A) (phenoxy) is studied by differential scanningcalorimetry in dynamic and isothermal tests attemperatures between 120 and 240
C. The addition of phenoxyto DCBA produces an increase in the reaction rateand a decrease in the temperature of maximum reactionrate for the uncatalyzed resin, and also for the system catalyzedwith copper (II) acetyl acetonate/nonylphenol. Theexothermic heat of curing for the mixtures is also dependenton the phenoxy content. These facts evidence a catalyticeffect of phenoxy on the curing of the cyanate esterresin, even though an autocatalytic behavior is observedfor all uncatalyzed DCBA/phenoxy mixtures. A simplifiedmechanistic kinetic model is used to calculate the kineticparameters. For the uncatalyzed systems, a decrease in thekinetic constant for the initiation reactions, and an increasein the propagation constant are measured when the cyanatecontent increases. The thermal activation energy forthe initiation reaction of the catalyzed systems is lowerthan that of the uncatalyzed ones, and it depends on theweight fraction of cyanate in the mixture. VC 2010 Wiley Periodicals,Inc. J Appl Polym Sci 000: 000–000, 2010