The cure kinetics of CTBN-modified epoxy system
Polimery 2000, No 1, 36
SummaryIn an epoxy system modified with a carboxyl-terminated butadiene acrylonitrile copolymer (CTBN) rubber, the cure kinetics was studied in terms of the Kissinger equation (eqn. 1) and of the autocatalytic cure rate expression (eqn. 2). By the former equation, a simple n-th order rate equation, OSC measurements allowed to determine the activation energy and the pre-exponential factor; by the latter equation, isothermal OSC analysis allowed to determine the rate constants and reaction orders. The two methods were found suitable to follow the cure kinetics of the epoxy system. In the system modified with CTBN, the cure rate was initially higher than that in the system with CTBN added, on account of the catalytic role of the -COOH groups in CTBN. At a degree of conversion equal to about 0.6, the cure rate was inverted on account of the formation of the CTBN domain.