Batch and semicontinuous emulsion copolymerization styrene/methyl methacrylate: Kinetics and viscoelastic properties

Abstract

Styrene(S)-Methyl methacrylate (MMA) COPO-lymers have been synthesized via batch and semicontinuous processes. The copolymers obtained in both processes were richer in styrene than the initial monomers composition. This fact is strongly influenced by the solubility of MMA in water. The experimental results also showed the existence of an inverse relationship between initiator concentration and molecular weight and consequently in the flow properties of the materials. Furthermore, the molecular Weight and flow properties did not show an important dependence on emulsifier content. It was found that the rate of copolymerization was an inverse function of the electrolyte present in the reaction medium. Comparison between copolymers made via batch and semiamtinwusly pointed out that in general the materials made in a batch process have lower viscosity and elasticity than its semicontinuous counterparts.