Temperature-structure Dependence of Poly(1-octene-co-t-butyl Acrylate) Prepared by Conventional Free Radical Polymerization

Aseries of poly(1-octene-co-t-butyl acrylate) were prepared by conventional free radical polymerization under mild conditions. The influence of different hightemperature decomposition initiators (e.g., t-butyl peroxybenzoate, di-t-butyl peroxide) on copolymer composition was above all investigated. Subsequently, poly(1- octene-co-t-butyl acrylate) was hydrolyzed to form amphiphilic poly(1-octene-co-acrylic acid). Thermal behaviours of poly(1-octene-co-t-butyl acrylate) and poly(1-octene-coacrylic acid) and micellar behaviours of poly(1-octene-co-acrylic acid) in water were investigated. By using high-temperature initiators the copolymerization temperature can be increased which results in incremental incorporation of 1-octene and monomer conversion. 1-Octene incorporation can be regulated in the range of 0~37.1 mol%. Meanwhile, molecular weights of these copolymers decreased as copolymerization temperature increased. The reactivity ratios of 1-octene (r1) and t-butyl acrylate (r2) were figured out as r1 = 0.005±0.001 and r2 = 9.016±0.035. CMC Value of poly(1- octene-co-acrylic acid) in water increased as their molecular weight and 1-octene incorporation were lowered. However, the mean hydrodynamic radius decreased as molecular weight increased or 1-octene incorporation dropped. Although Tg value of poly(1-octene-co-acrylic acid) is much higher than that of poly(1-octene-co-t-butyl acrylate), they all drop with the lowering of molecular weight or the increased 1-octene incorporation.