In situ block copolymer formation during solid-state shear pulverization: An explanation for blend compatibilization via interpolymer radical reactions

Interpolymer radical coupling leading to block copolymer formation is demonstrated for the first time in the solid state and in the absence of diffusion using solid-state shear pulverization. Fluorescence-detection gel permeation chromatography detected interpolymer reaction in high-molecular weight polystyrene (PS)/pyrene-labeled PS and high-MW poly(methyl methacrylate) (PMMA)/pyrene-labeled PS blends. Proof of interpolymer radical coupling supports prior pulverization studies demonstrating compatibilization, i.e., stability of dispersed-phase to long-time annealing, of PS/high density polyethylene and PS/PMMA blends.