Semi‐Continuous Emulsion Copolymerization of Styrene‐Butyl Acrylate with Methacrylic Acid: Box‐Behnken Design of Experiments

Abstract

AbstractA three‐factor three‐level Box‐Behnken design was conducted to study the semi‐continuous emulsion copolymerization of styrene (St)/butyl acrylate (BA) with methacrylic acid (MAA). The effects of St/BA ratio, MAA content, and pH on the carboxylic acid distribution in the latex, the polymer glass transition temperature (Tg), the average latex particle diameter, the molecular weight and distribution of the polymer products, and the coating adhesion to a polycarbonate substrate were investigated. The experimental results showed how the pH affected the distribution of MAA in the polymer particles. Regression analysis revealed how the St/BA ratio, MAA content, and pH influence the copolymer Tg, the latex particle size, the number‐average molecular weight Mn as well as the weight‐average molecular weight Mw. An empirical model to correlate the pull‐off adhesion of the latex coating to a polycarbonate substrate was developed.