Synthesis、Modification And Application Of Two-component Waterborne Acrylic Resin

In recent years,waterborne coatings have a rapid development for environmental protection,saving resources,low manufacturing cost and health.Acrylic resin is a widely used synthetic resin,because it possesses excellent durability,gloss retention,hardness and flexibility,it also occupies an important rule in the coating field.However,waterborne acrylic resin coatings in the process of practical application also have some defects,such as low solid content,high viscosity,low level of resistance to water etc.,that limited it widely application.In this paper,a new type of two-component waterborne acrylic resin that possesses low viscosity,high solid content,anti-flash corrosion and high level of resistance to water was synthesized via solution polymerization.The specific work is as follows:(1)The butyl acrylate(BA)and methyl methacrylate(MMA)are soft and hard monomer respectively,isooctyl acrylate(2-EHA)is plasticity monomer,maleic anhydride(MAH)and hydroxy ethyl methacrylate(HEMA)etc.are functional monomers,with free radical solution polymerization and semi-continuous drop process to prepare the waterborne acrylic resin.The effects of the type and loading of initiator,the ratio of soft and hard monomer,the method of adding,the reaction temperature,the neutralization degree on the resin properties was studied.Results show that when the dosage of initiator is 2 wt%(total mass ratio of monomer,similarly hereinafter),the ratio of soft monomer and hard monomer is 1.5:1,the loading of acrylic acid 6 wt%,the first stage reaction temperature 82～85℃,the second stage reaction temperature 85～90℃,neutralization degree of 100%,waterborne resin solid content of 50%,viscosity of 53 s,it possesses excellent properties in some respects.(2)The waterborne acrylic resin modified with glycidyl methacrylate(GMA)successfully synthesized via homogeneous solution polymerization.We explore the influences of different amount of GMA on properties of waterborne resin.The waterborne resin and coatings have been characterized by ATR-FTIR and 29 Si NMR instrument,and the curing mechanism of two-component waterborne resin was studied.The thermal properties of waterborne resin and solidified coating were analyzed by using DSC and TGA,it is found that GMA can not only effectively reduce the curing temperature of the coating,but also improve the heat resistance of the coating.Through the use of tensile test instrument and contact angle measuring instrument,it was found that GMA effectively improved the mechanical properties of the coating and changed the surface performance of the cured film,and improved the hydrophobicity of the coating.Finally,the amount of GMA was determined between 10 wt%and 15 wt%.(3)In this paper,a two-component high-gloss transparent varnish was developed by using modified waterborne acrylic resin as film material,mica powder and barium sulfate as fillers,water as solvent and tributyl phosphate as defoaming agent.The high-gloss transparent varnish has good physical and chemical properties,hardness of 3 H,cured film adhesion level is 0,flexibility is 0.5 mm,glossness reached 98%.The comprehensive properties of coatings have excellent performances.