Factorial experimental design for graft copolymerization of styrene and methyl methacrylate onto styrene–butadiene rubber

Abstract

ABSTRACT:The graft copolymerization of styrene (ST) and methyl methacrylate (MMA) onto styrene-butadiene rubber (SBR) latex prepared by seeded emulsion polymerization has been studied under various reaction conditions using cumene hydroperoxide redox initiator. The mechanism of graft copolymerization has been investigated. The synthesized graft copolymers were purified and then characterized by proton nuclear magnetic resonance ( 1 H NMR) analysis. A 2 2 IV 6 -2 fractional factorial experimental design was applied to study the effects of the process variables such as the amount of initiator and emulsifier, the presence or absence of chain-transfer agent, ST to MMA ratio, monomer to rubber ratio, and reaction temperature on the grafting efficiency. The analysis of the results from the design showed the sequence of the main effect on the observed response of the grafting of ST and MMA onto SBR and that the amount of chain-transfer agent had a significant effect. Transmission electron microscopy was used to study the morphology of the graft copolymers.

Synthesis of styrene‐g‐polyisoprene nanoparticles by emulsion polymerization and its effect on properties of polyisoprene composites

“…In addition, when the temperature was raised, the diffusion rate of ST monomers into the nanosized PIP was enhanced, resulting in higher GE. This result was similar to that reported for the graft copolymerization of MMA onto natural rubber and the graft copolymerization of ST and MMA on to ST–butadiene rubber (SBR) . However, some investigators reported a negative effect of high reaction temperature .…”

“…This result was similar to that reported for the graft copolymerization of MMA onto natural rubber [20] and the graft copolymerization of ST and MMA on to ST-butadiene rubber (SBR). [21] However, some investigators reported a negative effect of high reaction temperature. [22,23] They explained that the decomposition of the initiator increased with increasing reaction temperature, which caused an increase in both the number of free radicals and the rate of polymerization.…”

Prediction of styrene conversion of polystyrene/natural rubber graft copolymerization using reaction conditions: Central composite design versus artificial neural networks

“…There are four repeated runs at the central levels. The levels of these factors were chosen based on literature 10…”

“…To graft styrene and NR using free‐radical emulsion polymerization, redox initiator is the most suitable to initiate the graft copolymerization because it not only works well at high pH (the presence of ammonia in NR latex) but also is insensitive to the existence of oxygen in the system 8. Literature data indicate that the styrene conversion can be controlled by the graft copolymerization conditions—e.g., reaction time and temperature, amount of chain transfer agent (CTA), type of NR (deproteinized or NR), concentrations of monomers and initiators, and monomer‐to‐rubber ratio 8–10. Reaction mechanisms are generally developed to probe relationships between monomer conversion and polymerization conditions (e.g., concentrations of monomers, initiators and CTAs) 9, 11–13.…”

“…Reaction mechanisms are generally developed to probe relationships between monomer conversion and polymerization conditions (e.g., concentrations of monomers, initiators and CTAs) 9, 11–13. There are also other (less complicated) means to investigate the relationships without truly understanding the reaction mechanisms, such as response surface methods (RSMs) and artificial neural networks (ANNs) 8–10, 14–16…”