Synthesis And Properties Of HPMC Modified Silica-Sol/Polyacrylate Hybrid Emulsion

Inorganic/organic hybrid emulsion has the advantages in low price, safety, saving resources and energy, reducing environmental pollution and public nuisance, which is very common to be applied in various industries. However, the system still has many problems, such as the instability and poor film properties. In this paper, to improve the stability of inorganic/organic hybrid emulsion, we synthesized the stable silica-sol / polyacrylate hybrid emulsionwith silica-sol modified by hydroxypropyl methylcellulose(HPMC) and acrylic monomers as materials.We modified silica sol in an aqueous solution of HPMC and discussed modified temperature, Si O2 ratio with HPMC and HPMC content, which affected the appearance and the size of silica sol particle. Characterization results were given by using TEM, FR-IR and particle size. The results indicated that when HPMC modified temperature is 41℃, mass ratio of HPMC and Si O2 in the silica sol is 1:32, HPMC mass fraction of 0.15%, we obtained transparent and stable modified silica sol with an average particle diameter of 50.2 nm.HPMC modified sol / polyacrylate hybrid emulsion was prepared by in-situ emulsion polymerization method with HPMC modified silica sol and acrylate monomers. We investigatedthe effect of silicon content, monomer ratio, emulsifier type and ratio and other factors on the hybrid emulsion stability. When the system introduced semi-continuous method to drop monomers, it showed that the proportion of MMA:BA is 2:1, non-anion emulsifier ratio is 1:2, inorganic / organic hybrid emulsion with solid content is 35% and silicon content is 16% and average particle size is 151 nm. Storage stability and Ca2+ stability are good.Comparing HPMC modified silica sol/ polyacrylate hybrid emulsion films with unmodified silica sol emulsion film, we found that HPMC adsorption medium layer is formed on the surface of the Si O2 to make the combination of inorganic and organic closer. We got the film with good water resistance, hardness of 5H and the flexibility of 2mm.