Experimental study of the influence of the epoxy resin modification with additives on the contact angle

Influence of concentration of introduction the different industrial organic additives into the epoxy resin on wetting contact angle is studied experimentally. Epoxy resin ED-20 is modified with small concentrations of polydimethyl siloxane, OH-polymer silicone rubber, monoglycidyl ether of butyl cellosolve (Laproxide 301B), tris(2-chloroethyl) phosphate. The importance of these studies is related to the need to improve the adhesive properties of repair compounds based on epoxy resin, which are associated with the value of the contact angle. The contact angle of the resin drop is measured for glass, metal, asbestos cement, and concrete surfaces. The effect of the mass fraction of additives on the contact angle is more pronounced on smooth surfaces of dense materials, and less pronounced on rough surfaces of porous materials. It is observed that all dependences of contact angle on the mass fraction of additives in the range of 0.5-2% wt are linear. The linear equation theta=s.c+theta(0) describing the contact angle theta dependence on the mass fraction c of additives, which sufficiently fitting the experimental data with calculated coefficients s and theta(0), is found.