Preparation Of Polyacrylate/SiO₂ Nanocomposite Emulsion And Investigation Of Performance

Polyacrylate emulsion in a green environment-friendly emulsion.It is a resin which is made by the acrylic esters,methacrylic acid esters and other monomers. Polyacrylate has many good performance such as excellent weather resistance, good film-forming, bonding with the fabric easily and low cosr. But polyacrylate emulsion film has low hardness and thermal stability, film easier to back stick. As the nano-powders with unique properties, the introduction of emulsion system can significantly increase the rigidity of latex, hardness, strength, thermal stability, corrosion resistance, etc. In this paper, nano-SiO2 powder on the emulsion was modified to prepare nano-powders-polyacrylate composite latex. This results show that nano-SiO2 powder show that: Nano-SiO2 powder and emulsion, can be a good compound to form a stable polyacrylate composite latex. Add the KH550 silane and OP-10, 1% of the powder, the mechanical stirring plus ultrasonic dispersion can avoid nano-powders's agglomeration effectively.Taking into account the high polarity and surface energy of nano-powder, it can easily be absorbed and reunite together, forming secondary particles. This will larger nano-particles's size, which due to the loss of nano-powder's special features. The nanometer powder dispersion is first discussed in this paper, including the diapersion mechanism and many methods in detail. During the process of emulsion polymerization, nano-particles is added to modify the emulsion. The main research of this paper is the influence of different ratio nano-powder on the emulsion's properties and the coated glass cloth's alkali-resistance performance.Add the total weight of nano-SiO2 powder 1% of the dispersing agent OP-10 and surface modification agent silane coupling agent (kh-550), and using mechanical mixing method of combining the dispersed phase plus ultrasound can be effective in improving the phenomenon of agglomeration of nano-powders. When the reaction temperature is 78℃; core/shell ratio of 7/10; nuclear layer monomer (MMA/VAC/BA) ratio of 1/2/7; shell monomer ratio of 7/2/1; Nano-SiO2 Powder body dosage of 4‰, emulsifier dosage is 4%; initiator dosage is 1.1%; buffer dosage of 0.3%; de-ionized water consumption was 140% of the compound can form a stable emulsion in nature. When the nano-SiO₂ powder dosage is 4‰, the acrylic latex solid content, viscosity, stability, emulsion particle size distribution and emulsion adhesive force and so is ideal. the acrylic ester emulsion monomers are MMA,VAC and BA, the core ratio and shell ratio of MMA/VAC/BA is 1/2/7, 7/2/1 respectively, the core/shell ratio is 7/10, the amount of every components is: nanometer SiO₂ powder is 4‰, the water is 140%, the emulsifier is 4%, the initiator is 1.1%, buffer volume is 0.3%. When all this components are polymerized under 78℃, the composite latex is stable. Finally, composite emulsion is coated on the glass cloth to research it's comprehensive properties.