Synthesis, optimization, and characterization of poly (Styrene-co-Acrylonitrile) copolymer prepared via precipitation polymerization

Poly (Styrene-co-Acrylonitrile) (poly (St-co-AN) copolymer nanoparticles with controllable size are synthesized by a simple and cheap precipitation polymerization technique of styrene (St) and acrylonitrile (AN) monomers in aqueous medium using potassium persulfate (KPS) redox initiation system. Preparation of poly (St-co-AN) and studying all the parameters affecting the polymerization process such as time, temperature, monomer ratio, initiator molarity, cosolvent ratio, and solvent were considered. The resultant poly (St-co-AN) was compared with other studies which used different comonomers with AN, the comparison was assessed by evaluating the polymer conversion yield side. Maximum polymerization conversion yield, 66.5%, was obtained with St:AN (30%:70%) comonomer ratio. The smallest particle size obtained with this method was close to 16.17 nm and controlled by variation in polymerization conditions. The structure of poly (St-co-AN) copolymers were confirmed by Fourier transform infrared (FTIR), thermo gravimetric analysis (TGA), and differential thermal analyzer (DTA). The morphological structure of the copolymer particles was indicated by scanning electron microscope (SEM) photographs. The polymeric particle size was studied using particle size analyzer.