The Study On The Homo And Copolymerization Of Diethyl Vinylphosphonate

Phosphorus-containing polymers are particularly attractive for their extensive application in fuel cells, flame retardant and the biomedical field. Vinylphosphonate is one of the simplest vinyl monomers with phosphonate groups at the side chain. Since the late 1940s, different routes for vinylphosphonate synthesis have been reported. Researches on the polymerization of vinylphosphonates are following shortly after. To date, to the best of our knowledge, there is no report on the copolymerization of diethyl vinylphosphonate (DEVP) with 2-chloroethyl methacrylate (CEMA).Based on the previous work of our lab, the investigations into the effect of temperature on the polymerization of DEVP initiated by lanthanide tris(borohydride) complexes have been conducted. Higher molecular weight polymers can be obtained at lower temperature. The cloud point of PDEVP shows a strong dependence on the molecular weight, smaller molecular weight result in polymer solutions with a higher LCST.Herein, we synthesize a series of amphiphilic random copolymers, namely poly(diethyl vinylphosphonate-co-2-chloroethyl methacrylate) (P(DEVP-co-CEMA)), through free radical copolymerization using benzoyl peroxide (BPO) as initiator. The reactivity ratios for CEMA (M1) and DEVP (M2) are r1= 19.45, r2= 0.11. The structures and molecular characteristics of the obtained products are characterized by 1H NMR, FTIR and SEC analysis. The MALDI-ToF mass analysis further reveals that DEVP and CEMA units are randomly distributed in the copolymer chains. The self-assembly behavior of the P(DEVP-co-CEMA) copolymers in aqueous solution is preliminary investigated. The thermal properties of the P(DEVP-co-CEMA) copolymers are investigated by TGA and DSC measurements.Furthermore, with initiating haloalkyl groups, graft copolymers P(DEVP-co-CEMA)-g-PS can be prepared via atom transfer radical polymerization (ATRP) using P(DEVP-co-CEMA) as macroinitiator. The structures of the graft copolymers are confirmed by 1H NMR, GPC and DSC analysis.