Morphology and grafting in polybutylacrylate‐polystyrene core‐shell emulsion polymerization

Abstract

Abstract The morphology of polybutylacrylate–polystyrene (PBA–PS) core‐shell latex particles prepared by seeded emulsion polymerization was investigated as a function of the addition method of styrene (St). The thin layer chromatography/flame ionization detector (TLC–FID) technique was used to characterize the morphology of the core‐shell latexes. It was found that grafting PS to the PBA core occurs during seeded emulsion polymerization. The percentage of grafting depended on the method of addition of St, being greatest for the batch reaction, less for the preswollen batch reaction, and least for the semibatch reaction. Upon aging the PBA core‐polymer migrated out of the latex particles with a low degree of grafting to form dumbellshaped particles, whereas the PBA–PS core‐shell particles with a high degree of grafting remained spherical because of the emulsifying ability of graft copolymer.