Synthesis and characterization of core (PBA)/shell P(MMA-ITA) latex particles via seeded emulsion polymerization

A novel core/shell latex particle was successfully prepared by seeded emulsion polymerization. The rubbery core was made of poly (butyl acrylate) (PBA) with a slight cross-linked structure, while the glassy shell was poly (methyl methacrylate) (PMMA) containing a small amount of itaconic acid (ITA). The resulting core/shell latex particle PBA/P(MMA-ITA) should possess the function both of toughening the PBA core and the compatibilization of P(MMA-ITA) shell as well. The latex particles were characterized by transition electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and non-aqueous acid-base titration. The results showed well-defined core/shell morphology with the diameter of 50 similar to 65 nm and the cross-linkers diethylene glycol diacrylate (DEGDA), diallyl phthalate (DAP), and trihydroxymethylpropyl triacrylate (TMPTA) appeared the highest cross-linking efficiency. The monomer ITA has copolymerized with MMA successfully, and P(MMA-ITA) copolymer has been linked onto the surface of PBA core both by chemical bond and physical adsorption. The PBA/P(MMA-ITA) latex particles were core/shell structure indeed, and varying the ITA dosage and core/shell proportion, its size, T-g, and ITA content in shell layer would change relatively.