Copolymerization of styrene with nonionic surfactants: Poly(ethylene oxide) macromonomers

Abstract

A series of macromonomers of ω-methoxy poly(ethylene oxide)n undecyl-α-methacrylate (PEO-R-MA-n, where n = 10, 15, 40) was synthesized. The copolymerization of styrene (M1) with the macromonomers (M2) was carried out in benzene solution and in an emulsion. The apparent reactivity (1/r1) of the macromonomer decreased with an increase of its PEO chain length. The results are discussed in terms of the incompatibility between PEO macromonomer and polystyryl radicals. Stable emulsion latices with monodisperse particles were obtained from the copolymerization of styrene with PEO-R-MA-40. The particle sizes ranged from about 30 to 300 nm in diameter depending on the amount of styrene used and the PEO chain length of the macromonomer. The molecular weights of the copolymers produced by the emulsion copolymerization of PEO-R-MA-40 with styrene were around half a million, and their molecular weight distributions (M̄w/M̄n) were relatively narrow (1.6-1.9) as determined by gel-permeation chromatography.