Synthesis Of Polysiloxanes Emulsion With Branch And Study On Its Composite Characterization

Polysiloxane has been widely used in many domains such as silk fabric, leather, coating and light-sensitive materials, which is attributed to the continuous improvement of theory and technology research. The weaknesses in ordinary polysiloxane such as low solid content, poor stability are too much to extensive application. The weaknesses of polysiloxane were gradually worked out motivated by the development of theory research, and its great application value appeared wildly.The water-borne epoxy resin and polyester (made in laboratory) were used to react to the ethyl orthosilicate and hydroxyl-terminated poly dimethyl polysiloxane to synthesise the polysiloxane contained two kinds of branched chain, which was operated under the catalyzer. Then the mated polysiloxane was emulsified through Mechanical Alloying. The FTIR was used to analyze the structure of the made polysiloxane for manifesting the hydrophilic group on branched chain or not. The stability of the polysiloxane contained branched chain was detected, meanwhile, the influence of raw material proportion and emulsifier to emulsion stability was detected. Then we researched the influence of compound of the made emulsion and acrylate emulsion to film-forming property. The results indicated that the best stability was obtained as Ethyl orthosilicate0.15and Waterborne epoxy resin (or polyester): hydroxyl silicone oil=10:90(mass ratio), meanwhile the viscosity was3545mPa-s and the put time tenderness exceeded7days. The tensile shear strength reached2.2MPa as add the water-based epoxy modified polysiloxane quantity for five copies at80℃for2h, meanwhile, the tensile shear strength and the elongation at break reached an equilibrium level, with1.1MPa and8.5%.epoxy resin is wildly used in all aspects of the national economy because of the excellent bonding strength, mechanical and electric properties, although it’s very brittle and weather resistance and high temperature resistant performance is poorer. Considering that the polysiloxane can offset those disadvantages, we implemented the physical blending modification in the compounds of polysiloxane and epoxy resin. The results show the declined hardness of the composite system, the slightly decreased tensile shear strength and a significantly elevated elongation at break with the increase of polysiloxane. The glass transition temperature increase to12%,32.7%,42.8%with the introduce of Water-based epoxy modified polysiloxane and the glass transition temperature increase to2.9%,15.5%,19.3%with the introduce of polyester modified polysiloxane, respectively, in the epoxy resin system. The result is attributed to the higher bond energy of Si-O in polysiloxane, which is benefit to promote the heat-resistant quality of the epoxy resin system.