Water soluble well-defined acidic graft copolymers based on a poly(propylene glycol) macromonomer

A series of well-defined amphiphilic graft copolymers based on poly(propylene glycol)methacrylate (PPGMA) extended with a polymethacrylate segment containing methacrylic acid units was successfully synthesized, combining atom transfer radical polymerization (ATRP), esterification, "grafting from" polymerization, and acidolysis. The multistep procedure yielded hydroxy-functionalized polymers (6-47 mol% of PPGMA), bromoester-functionalized copolymers as multifunctional macroinitiators (n_Br = 8-25), PPGMA-based copolymers with poly(tert-butyl methacrylate) (PtBMA) segments (DP_tBMA = 18-59), and copolymers varying in hydrophilic fraction content (F_MAA = 0.28-0.54). After the generation of methacrylic acid units the PPGMA-based graft polymers attained a good solubility in polar solvents such as methanol and water. The particles, which were formed in aqueous solution, achieved sizes in the nanoscale range (165-230 nm) and negative zeta potentials.