Atom Transfer Radical Polymerization of Dimethyl(1-ethoxycarbonyl)vinyl Phosphate and Corresponding Block Copolymers

Atom transfer radical polymerization (ATRP) of dimethyl(1-ethoxycarbonyl)vinyl phosphate (DECVP) was investigated in the presence of different catalyst systems and initiators. Polymers with controlled molecular weight and relatively low polydispersity (PDI < 1.5) were obtained through ATRP initiated with ethyl 2-bromoisobutyrate (EBriBu) in the presence of Cu(I)Cl/2,2‘-bipyridine (bpy). Faster polymerization and higher monomer conversion were obtained in the polymerization using Cu(I)Cl/ N,N, N ‘, N ‘ ‘, N ‘ ‘-pentamethyldiethylenetriamine (PMDETA) or Cu(I)Cl/1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA) as the catalyst system. PDECVP dissolves in water below 70 °C, but its lower critical solution temperature (LCST) depends on the polymer concentration. The conversion of PDECVP to poly((1-ethoxycarbonyl)vinylphosphonic diacid) (PECVPD) was accomplished by reaction with bromotrimethylsilane followed by methanolysis. Block copolymers, PDECVP- b -poly(styrene) (PS), PDECVP- b -PS- b -PDECVP, and PDECVP- b -poly(methyl methacrylate) (PMMA), were synthesized by extending from PS−Br, Br−PS−Br, and PMMA−Br macroinitiators. The controlled block copolymers were obtained, PDECVP- b -PS with M n = 40 500 g/mol and PDI = 1.4, PDECVP- b -PS- b -PDECVP with M n = 41 500 g/mol and PDI = 1.23, and PDECVP- b -PMMA with M n = 29 700 g/mol and PDI = 1.08. Initiation efficiency exceeded 94% using PMMA−Br as the macroinitiator.