Polysiloxane nanoparticles prepared by emulsion polymerization under microwave irradiation

Abstract

AbstractEmulsion polymerization of octamethyl cyclotetrasiloxane (D4) under microwave irradiation (MI) was studied. The polysiloxane (PSi) nanoparticles via cationic ring-opening polymerization of D4 were obtained by using the dodecylbenzene sulphonic acid (DBSA), sodium dodecylbenzene sulphate (SDBS) and poly(ethylene glycol) monooctylphenyl ether (OP-10) as the catalyst and the emulsifiers respectively. The particle size analyzer and transmission electron microscope (TEM) were used to determine the particle size of PSi emulsions. The results show that, the particle size of PSi emulsions prepared under MI is substantially smaller and the particle distribution is narrower compared with that under conventional heating (CH). With the aid of MI, the polymerization rate and the equilibrium conversion are enhanced. The polydispersity index (PDI) and molecular weight (Mw) measured by GPC indicate that under MI, PDI of PSi is narrower and Mw of PSi at high temperature is lower than those under CH.