Preparation Of High Performance Polyacrylate/SiO₂ Hybrid Emulsion

With the improvement of people's quality of life,more attention has been paid to the water-based coatings,which is the environmental protection and safety.It has been reported that polyacrylate/nano SiO₂ hybrid emulsion shows superior performance than ordinary hybrid emulsion.How to make the hybrid emulsion with good film performance is still the research hotspot.This paper was produced hydroxy-containing polyacrylic/nano SiO₂ hybrid emulsion with good emulsion stability and film performance,and studied the effect of hybrid emulsion formula and emulsion polymerization parameters on the coating film.First,the hydroxy-containing polyacrylate/nano SiO₂ hybrid emulsion was prepared with methyl methacrylate?MMA?,butyl acrylate?BA?,silica sol and hydroxyethyl methacrylate?HEMA?via seeded emulsion polymerization.The performance of the hybrid emulsion and its coating were characterized.When the dosage of silica sol is 8%and the dosage of HEMA is 4%,the appearance of the emulsion is milky white with blue light,the freeze-thaw stability,Ca²⁺stability,centrifugal stability and storage stability of the hybrid emulsion are the best.The gel rate of emulsion polymerization is 0.7%.The film prepared by the hybrid emulsion is colorless and transparent.The hardness of the coating is 4H,adhesion force is 0,and the water absorption rate is 3.7%.The performance of hydroxy-containing polyacrylate/nano SiO₂-amino resin varnish coating was tested,and the effect of mass ratios of the hybrid emulsion and amino resin curing agent on the performance of the coating were studied.When the mass ratio of the hybrid emulsion is 80%and the curing agent of methyl ether resin is 19%,the film of polyacrylate/nano SiO₂-amino resin paint film shows the best hardness,adhesion,water resistance,and solution medium.The resistance to neutral salt spray was found in.Crosslinking reaction between the hybrid emulsion and amino resin curing agent is confirmed by the infrared spectrum analysis and DSC test.The glass transition temperature of film polymer increased due to the multiple crosslinking system.The results of TGA test show that the heat resistance and stability of the film are improved.