Synthesis, morphology and rheology of core-shell silicone acrylic emulsion stabilized with polymerisable surfactant

Abstract

Core-shell silicone acrylic emulsions with 3-methacryloxypropyl trimethoxysilane (MPTS) in the shell were pre- pared by seeded polymerization with the assistance of polymerisable maleate surfactant (MT). Fourier transform infrared (FT-IR) demonstrated the incorporation of polymerisable surfactant in copolymer. It was found that small amount of octadecyl acrylate was beneficial to emulsion stability with decreasing the particle size from 194.6 to 165.7 nm. It was also found that the particle size increased from 165.7 to 242.9 nm with the increase of MPTS concentration. Furthermore, rheo- logical measurement indicated that the emulsion was endowed with pseudoplasticity. At low shear rate, marginal reduction in viscosity was detected when MPTS concentration increased to 2%, while great increase in viscosity was observed with higher MPTS concentration, the interaction force among emulsion particles became the predominant factor instead of par- ticle size. In addition, better water resistance was observed when MT concentration was lower than 1.5%, and MPTS con- centration higher than 2%. Moreover, surface roughness was increased with MPTS addition, the crosslinking among core and shell reconstructed the surface morphology of film.