Journal of Applied Polymer Science, Vol.82, No.6, 1521-1540, 2001
Kinetic studies on styrene-divinylbenzene copolymerization by suspension technique
Kinetic studies on styrene and divinylbenzene (DVB) copolymerization by the suspension technique in a toluene diluent initiated by benzoyl peroxide are reported. Evaluation of the important reaction parameters is carried out. The crosslinked styrene-DVB copolymers can absorb toluene to a maximum swelling ratio of 17. The absorption/desorption took place instantaneously and reached the maximum value within 10 min, and it could be repeated many times, yet gave the consistent result. Rate equations evaluated by both integral and differential methods are investigated. High monomer orders of 1.5-2.3 were obtained. The activation energy for the polymerization was about 40 kcal/mol(-1). Autoacceleration was found even at low conversions. The acceleration was influenced by both monomer, crosslinker, and initiator concentrations. The integral and differential methods for the rate evaluation were compared, and the relationship between the rate equation and polymerization behavior was elucidated. The kinetic orders determined for this copolymerization show considerable deviation.
Keywords:kinetic studies;styrene;divinylbenzene;ethyl vinylbenzene;rate equation;integral method;differential method