![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
Abstract
Free radical-initiated copolymerization of diethyl vinyl phosphate (DEVPA) with vinyl acetate (VAc) and acrylonitrile (AN) was studied. The monomer reactivity ratios for the monomer pairs, determined at 60°C using benzoyl peroxide as an initiator, are: r1(VAc) = 0.95, r2(DEVPA) = 0.93; r1(AN) = 6.6, r2(DEVPA) = 0.049. The values of the Alfrey-Price constants, Q and e, for DEVPA were calculated to be 0.025 and 0.13, respectively, from the VAc system, and 0.026 and 0.14, respectively, from the AN/DEVPA pair. These results indicate that the general reactivity of DEVPA is almost the same as that of VAc and that the diethylphosphate group is a stronger electron-attracting group than the acetoxy group. The intrinsic viscosity and number-average molecular weight of copolymers decreased as their content of DEVPA units increased, indicating a high degree of chain transfer caused by DEVPA.