Kinetics of synthesis and organic solvent absorption-desorption of styrenic imbiber beads

Abstract

This research investigates the kinetic of syntheses of styrene-divinylbenzene copolymer leads for absorption and desorption of organic solvents with the solubility parameters in the range of 18+-1 (MPa) 1/2. Benzoyl peroxide, toluene and poly (vinyl alcohol) are used as initiator, diluent, and suspending agent, respectively; while styrene and divinylbenzene are used as monomer and crosslinking agent, respectively. Monomer-to-aqueous phase is 1:7 by weight, and the polymerization time and temperature, and agitation speed are varied. Bench-scale experiments are carried but first to obtain the suitable information for a pilot-scale production. The reaction parameters of kinetic studies are the concentration of initiator, polymerization temperature, agitation speed, the concentrations of crosslinker and diluent. The raw data are analyzed for influencial parameters for the syntheses using an SPSS program for Windows at the level of significant, alpha = 0.05 at 95% level of confidence. The statistical analysis reveals that the concentration of initiator, polymerization temperature and diluent affected the syntheses. Differential investigation for evaluating the rate of the copolymerization, r discloses the following rate expression: -r alpha CSty 1.9 CDVB 1.8 CEVB 1.8 for the organic solvent absorption and desorption (in toluene), the beads can swell to a miximum value of 17 times their organical volume within 60 min, and have a diffusion coefficient of 1.39x10 -5 - 1.49x10 -5 cm2 s. They also can desorb the solvent withni 40 min The bead from scale-up production can only swell to their maximum size of 7