화학공학소재연구정보센터
Journal of Adhesion Science and Technology, Vol.32, No.17, 1861-1875, 2018
Properties of a PVAc emulsion adhesive using a nonphthalate plasticizer obtained by condensation of 2-methylpropanal
The requirement to search for new plasticizers and coalescents for making water-based dispersion adhesives from poly(vinyl acetate) is of particular importance, especially now, after banning all kinds of toxic phthalates and restricting the use of glycol derivatives classified as volatile organic compounds. The poly(vinyl acetate) adhesive was synthesized using the eco-safe plasticizer - 3-hydroxy-2,2,4,-tri-methyl pentyl isobutyrate. The plasticizer was obtained by aldol condensation of 2-methylpropanal, byproduct of oxy synthesis from propylene. Its desirable properties were confirmed by comparing the composition of the adhesive comprising poly(vinyl acetate) as the principal component and the plasticizer as the additive. 3-hydroxy-2,2,4,-tri-methyl pentyl isobutyrate and commonly known plasticizers, such as: diisobutyl phthalate and diethylene glycol n-butyl ether acetate were used as the plasticizers in the experiment. The adhesives were compared in respect of the following parameters: dry weight, pH, viscosity, minimum film forming temperature, penetrability, setting time and stability in time. The test results indicate that 3-hydroxy-2,2,4,-tri-methyl pentyl isobutyrate can be used successfully as a plasticizer for making wood adhesives in the range from 2.0 to 2.5% of the adhesive formulation and for making bookbinding adhesives in the range from 4.7 to 5.6% of the adhesive formulation. This enables an about twofold reduction of the amount of the plasticizer, in comparison with the adhesive based on diisobutyl phthalate. 3-hydroxy-2,2,4,-tri-methyl pentyl isobutyrate can be used in dispersion adhesive formulations, thus replacing the undesirable, toxic phthalate esters and polyglycol derivatives classified as volatile organic compounds.