β-Hydroxypropyl acrylate (HPA) and styrene (St) were copolymerized with ABIN as initiators. The reactivity ratios of the monomers were determined by several methods and the following data were obtained:γHPA-0.36
rSt = 0.45 (Mayo Lewis method); rHpA = 0-32
rst = 0.48 (FR method); rHPA = 0.34
rst = 0.46 (YBR method); rHpA = 0.33
rst = 0.48 (K-T method). Sequence distribution of HPA-St copolymer were also studied.