Performances of Polyvinyl Acetate Hybrid Emulsions with Nanoparticles SiO<sub>2</sub>

Abstract

Polyvinyl acetate（PVAc）hybrid emulsions with nanoparticles SiO2 were prepared by the semi-continuous seeding emulsion polymerization. The micro-morphologies of the hybrid emulsions, the diameters and distributions of the latex particles were characterized with the aid of scanning electron microscope (SEM) and diameter analyzer. Adhesive properties of hybrid emulsions and the properties of the emulsion films were determined by mechanical properties tester and dynamic mechanics analyzer (DMA). And the rheological behaviors of hybrid emulsions were measured via rheometer. SEM and diameter analysis showed that the process of the nanoparticles SiO2 by ultrasonic made a good dispersibility of latex particles in emulsions, diameters of the latex particles were 0.68~0.89μm with the content of SiO2 from 0 to 1.0% (% in relation to the total mass VAc), and indexes of distributions of particle size were increased with the increasing of the content of SiO2 from 0 to 1.0%. Adhesion strengths of PVAc emulsions modified with nanoparticles SiO2 were improved. DMA results indicated that the films of PVAc/SiO2 hybrid emulsions had the higher storage modulus than the film of PVAc, the temperatures of glass transition of the films of PVAc/SiO2 hybrid emulsions were not changed obviously, and the water absorptions of films were decreased. Rheological results revealed that flow consistency indexes were increased then decreased with the increasing of the content of SiO2 from 0 to 1.0%, and PVAc/SiO2 hybrid emulsions were typical pseudoplastic fluid.