ABSTRACT
Hydroxyl acrylic monomers are important because the hydroxyl group present in the molecule can react with isocyanate groups, conferring better mechanical properties to the final polymer when applied onto some substrates. The aim of this work was to study the effects of the hydroxypropyl acrylate (HPA) and hydroxypropyl methacrylate (HPMA) monomer concentration on the emulsion polymerization of styrene (St) with n-butyl acrylate (ABu) and acrylonitrile (ACN). The goal of this work was to obtain latexes with higher concentrations of hydroxyl groups, ideal for reacting with isocyanate, without generating residues or coagulum. Latexes with different amounts of HPA and HPMA (0,3,5,7 e 10 wt%) were obtained and characterized with respect to solids content, viscosity, particle diameter, particle size distribution, freeze-thaw stability, minimum film forming temperature, coagulum formation, hardness and colloidal stability. The results show that the increased HPMA concentration affected the colloidal properties of the latexes. Among the concentrations of HPMA studied, it was possible to obtain latex with a maximum concentration of 5% HPA and 7% HPMA, whereas latex produced with 10% HPA and HPMA had low colloidal stability. Adhesives was obtained by mixing styrene-acrylic hydroxylated latex with a blocked poly(isocyanate) dispersion and characterized.
Keywords
Emulsion polymerization; hydroxylated latex; hydroxypropyl acrylate; hydroxypropyl methacrylate; blocked isocyanate
