Micellization of graft copolymers of alkyl methacrylates with alpha-methyl-omega-hydroxypoly(oxyethylene) methacrylates

The solution properties of graft copolymers having a poly(methyl methacryla te-co-lauryl methacrylate) backbone and poly(oxyethylene) branches of diffe rent compositions were studied by static and dynamic light scattering metho ds in ethanol-water mixed solvents. The graft copolymers formed multimolecu lar aggregates in mixed solvents with water content higher than or equal to 10 vol%. The difference in solubility of lauryl and poly(oxyethylene) side chains of copolymers seems to be a dominant factor in determining their as sociation behavior. The micelle formation is preferred in such solvents (wa ter content greater than or equal to 30 vol%) where the difference in solub ilities of LAM and PEO side chains on graft copolymers is higher than a cri tical one. In conditions where there is a lower difference in solubilities of the side chains (water content 10-20 vol%), the random association of co polymers dominates. Copolymers were fully soluble in ethanol with low water content (1 vol%). The highest association number of micelles and consequen tly the lowest polydispersity were obtained with copolymers having the long est PEO side chains (M-w = 5000 g mol(-1)). (C) 1998 Academic Press.