Synthesis and characterization of copolymer of styrene and acrylonitrile by emulsion and microemulsion polymerization using different emulsifiers

Abstract

Stable poly(styrene/acrylonitrile) (SAN) latexes were produced by polymerization of styrene and acrylonitrile in emulsion and microemulsion using sodium dodecyl sulfate and potassium oleate anionic emulsifiers. Their chemical structure, morphology and thermal behaviour were inspected by fourier transform infrared spectroscopy, scanning electron microscopy, thermo-gravimetric analysis and differential scanning calorimeter analysis respectively. Fourier transform infrared spectroscopy analysis verified the successful formation of copolymers of poly(styrene/acrylonitrile). The addition of different emulsifiers and acrylonitrile to the polystyrene improves its structure and thermal stability. Copolymer produced by microemulsion polymerization of styrene and acrylonitrile was found to be more thermally stable with higher molecular weight and molar mass and long range ordered microporous morphology with the reduction of particle size from 2-12 nm to 1-10 μm as compared to other copolymers synthesized by emulsion polymerization.