Thermooxidative decomposition and its kinetics on chlorinated natural rubber from latex

Thermooxidative decomposition and its kinetics on chlorinated natural rubbe r (CNR) from latex are studied by thermal gravimetry (TC) analysis and TG c oupled with FTIR spectroscopy. The thermooxidative decomposition of CNR is a two-step reaction. The first step is the reaction of dehydrochlorination of which the reaction order (n) is 1.1; the reaction activation energy (E) increases linearly with the increment of the heating rate (B), and the appa rent activation energy (E-o) is 101.7 kJ/mol. The initial temperature of we ight loss (T-o) is 1.29B + 248.7, the final temperature of weight loss (T-f ) is 0.86B + 312.4, and the temperature at the maximum weight loss ratio (T -p) is 1.05B + 286.2. The decomposition ratio at T-p (C-p) is not affected by B, and its average value is 38%. The decomposition ratio at T-f (C-f) is also not affected by B, and its average value is 60%. The second step is a n oxidative decomposition reaction of the molecular main chain. The value o f n is 1.1, E increases linearly with the increment of B, E-o is 125.0 kJ/m ol, the relation between B and T is similar to that of the first step, and C-f approaches 100%. (C) 2001 John Wiley & Sons, Inc.