Synthesis of Modified Poly(vinyl acetate) Adhesives

Abstract

Modified poly(vinyl acetate) copolymers with drying oils as comonomers have been prepared. The unsaturated triglycerides can produce cross-linking and give a waterproof effect due to their hydrophobicity. The new copolymers synthesized by solution polymerization in an organic medium have been submitted to analytical characterization in order to investigate the role of the drying oils in the polymerization reaction. NMR spectroscopy has been used to obtain information on the structure of the polymerization products and to confirm the eventual C–C bond formation between vinyl acetate and triglycerides. Spectroscopic data are found to be in agreement with copolymer formation. Copolymers as water dispersion have also been synthesized by emulsion polymerization in presence of poly(vinyl alcohol) as protective colloid and evaluated as wood adhesives. The corresponding polymer films have been subjected to mechanical characterization. An improvement in the water and solvent resistance has been observed due to the presence of drying oils. The cobalt acetate, if present as catalyst in the adhesive formulation, promotes cross-linking and produces a positive effect on the adhesive performance.