Synthesis and characterization of an alkoxy and methacryloxy propyl terminated polydimethylsiloxane for uses in the core-shell latex particles

Alkoxy and methacryloxy propyl end caped polydimethylsiloxane (AMP-PDMS) was successfully synthesized. The preparation included four steps, which are hydrolysis, hydroxyl formation, alkylation and alkoxylation. Then, the latex particles with a polyacrylate core and a polydimethylsiloxane shell via AMP-PDMS as the space arm to link the core and shell have been prepared by semi continuous seeded emulsion polymerization. And several key polymerization reaction conditions such as the surfactant content, AMP-PDMS concentration, feeding sequence and the acrylates/siloxanes ratio were detailedly discussed. Also the optimal condition to prepare stable core/shell particles was selected and a proper preparation process has been established. The as-synthesized particles were characterized by TEM and laser light scattering. The clear core/shell structure of the particles could be observed through analysis TEM. In addition, the obtained results manifested that siloxanes had been grafted on the surface of the polyacrylate particles and they distributed on the outmost layer of the particles. Finally, the surface hydrophobicity of the film formed by latex particles was investigated by the water absorption ratio measurement. The results indicated the developed latex particle provided with a fair water-repellency property.