The effect of modifiers on the stability of a vinyl acetate/ethylene copolymer dispersion

This paper examines the effect of modifiers on the stability of a vinyl acetate/ethylene copolymer dispersion adhesive upon aging. Eighteen common modifiers were added to a well-characterized vinyl acetate/ethylene copolymer dispersion (Dur-O-Set^® E-150) in known concentrations and dry-film samples were subjected to 16–17 years of dark aging and seven to eight years of light aging. Yellowing, pH, gloss, swelling, cohesive strength, and flexibility were monitored for changes upon aging. Generally, the neat Dur-O-Set^® E-150 (no additives) was found to become acidic on aging, but was fairly resistant to yellowing. It also swelled substantially in toluene, was of high gloss, medium strength, and flexible, and remained so on aging. No modifier was found to improve these properties. Various solvents, wetting agents, and thickeners did not alter the properties by much, while plasticizers, freeze-thaw stabilizer, glycerin, and certain fillers had a more negative effect.     

The evaluation of selected poly(vinyl acetate) and acrylic adhesives: A final research update

Abstract

The final report on the Canadian Conservation Institute's poly(vinyl acetate) and acrylic adhesive research is given after 25–27 years of dark aging and 12–15 years of light aging. A total of 27 poly(vinyl acetate) and 25 acrylic adhesives were tested for pH, volatile emissions (mostly acetic acid), flexibility, strength, and yellowing after aging. In 1996, the work was first published after three to five years of aging data had accumulated. Measurements for pH, yellowing, strength, and flexibility were recently repeated again and these results are reported here. These new data points are reported to provide insight into the effect of these longer aging periods on the products included in the study. As well, the most stable (according to set criteria) poly(vinyl acetate) and acrylic adhesives tested are revealed, which, except for a few products, do not differ greatly from those reported in 1996.