A Mathematical Model of the Bulk Copolymerization of Styrene and Acrylonitrile in the Presence of Polystyrene‐block‐Polybutadiene

Abstract

The bulk copolymerization of styrene and acrylonitrile in the presence of SB using BPO as initiator was investigated. Reactions were carried out at 80 °C with different initial SB concentrations. Global variables, such as conversion and cumulative grafting efficiency of SAN, were determined during the prepolymerization. The isolated non‐grafted SAN was also analyzed to determine its average molar masses and composition. A mathematical model was developed, and theoretical predictions were compared with experimental data. A good agreement between measurements and simulations was obtained from a heterogeneous model when BPO was evenly distributed between phases.magnified image

Graft Copolymerization of Styrene and Acrylonitrile in the Presence of Poly(propylene glycol): Kinetics and Modeling

“…All SAN is considered to be in the dispersed phase. The terminal model is used although the penultimate effect is often significant in copolymerization of St and AN 51, 52. The polymeric radicals undergo termination exclusively by recombination 9, 29 A narrow molecular weight distribution (MWD) of PPG and macromer is assumed. The number of SAN chains per graft copolymer is one 9…”

“…The terminal model is used although the penultimate effect is often significant in copolymerization of St and AN 51, 52. The polymeric radicals undergo termination exclusively by recombination 9, 29…”

“…Besides classic copolymerization mechanism of St and AN,29 the present copolymerization mechanism should include transfer reaction from primary and non‐graft polymeric radicals to backbones of PPG and macromer and copolymerization of monomers with macromer terminal double bonds 4. Homo‐polymerization of macromer is neglected due to its very large steric hindrance.…”

“…Polymerization in the continuous phase is considered to obey to the rules of free radical solution polymerization and the kinetic parameters are chemical controlled 14, 15, 29. Most kinetic parameters can be taken from literature (Table 3).…”

“…So, the gel effect, the cage effect and even the glass effect need to be considered, modeling of which are reviewed by Achilias 23. A semi‐empirical model based on the free volume theory originally developed by Hamielec and coworkers24–27 is often used to estimate the diffusion‐controlled reaction rate coefficients 21, 28, 29. Based on Fickian description of reactant diffusions, a well known diffusion‐controlled model, originally derived by the group of Soong and coworkers30–32 and extended by Achilias and Kiparissides (CCS‐AK),33, 34 is widely applied in high viscosity polymerization systems 14, 15, 35–40.…”