Copolymerization of 2-[3-(2H-Benzotriazol-2-yl)-4-hydroxyphenyl]ethyl Methacrylate with Styrene

Radical copolymerization of 2-[3-(2 H -benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate (M 1 ) with styrene (M 2 ) at 70 °C in 1,4-dioxane was investigated and the reactivity ratios were determined. The copolymerization was carried out as batch copolymerization to a low conversion or as copolymerization with a continuous addition of monomers at higher instantaneous conversion. The monomer reactivity ratios of the copolymerizable UV stabilizer 2-[3-(2 H -benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate with styrene were determined using the Finemann-Ross plot for both copolymeration techniques. The estimated reactivity ratios were r 1 = 0.588 and r 2 = 0.6 for the technique of continuous addition of monomers and r 1 = 0.462 and r 2 = 0.476 and for the batch experiment. The copolymerization exhibited an azeotrope at f 1 = 0.507, thus a copolymer with microstructure close to the alternating one was formed at this ratio of comonomers.