Isothermal polymerization kinetics of N,N′-bismaleimide-4,4′-diphenylmethane with cyanuric acid

Kinetics of polymerization of N,N'-bismaleimide-4,4'-diphenylmethane (BMI) with cyanuric acid (CA) in N-methyl-2-pyrrolidone (NMP) was investigated. Both model-free and model-fitting methods were used to determine the relevant kinetic parameters. For the model-free method, the average activation energy (Eu) and pre-exponential factor (A(alpha)) are 23 +/- 1 kJ mol(-1) and 162 +/- 2 min(-1) in the a range 0.1-0.9, respectively. The A(alpha), value obtained is a result of the model assumption with g(alpha)= -In(1 - alpha) [i.e. f(a)= (1 - alpha)], which is based on H-1 NMR measurements. As to the model-fitting method, the overall activation energy (E) and pre-exponential (A) are 23 kJ mol(-1) and 166 min-1 with g(a) [(1 - alpha)(0.15) - 1]/0.15 {i.e. f(a)= (1-alpha)(1.15)}. The polymerization kinetics and mechanism of BMI/CA in NMP were characterized by DSC. Furthermore, complementary 1H NMR and C-13 NMR techniques were used to identify the chemical structure of CA in the reaction medium and, therefore, the reaction mechanism (model) was predicted. (C) 2016 Elsevier B.V. All rights reserved.