Effect of diisocyanate type in thermal and mechanical properties of acrylic/polyurethane hybrid

PERUZZO, P.J.; ANBINDER, P.S.; GAMBINO, L.G.; AMALVY, J.I.

Los Cocos

Simposio; ARCHIPOL´09 (V Simposio Argentino-Chileno de Polímeros); 2009

Polyurethane-based coating systems have an established place in the coatings industry. The main reason for this is because of the high gloss of their products. They also combine outstanding resistance to solvents and chemicals with good weather stability. Due to new developments in urethane chemistry and efforts to reduce emissions there is increasing interest in the development of environmentally-friendly water-borne coatings. Despite there are water-borne polyurethane-based products, the industry is still looking for low-cost products. Incorporation of acrylic monomers leads to cost reduction and properties are affected depending on the amount and on the way of incorporation. Physical blends of preformed acrylic and polyurethane dispersions were prepared, but film-forming properties are not satisfactory (Coogan et al., 1994) The polymerization of acrylic monomers in the presence of preformed polyurethane chains with polymerizable terminal vinyl groups is a useful synthetic method to achieve better film-forming properties and products are known as polyurethane-acrylate or acrylic-polyurethane hybrids (Guyot et al., 2007; Wang et al., 2005). These hybrid systems should produce binders with better technological properties than those obtainable from physical mixtures. In this work, the characterization of hybrids acrylic/polyurethane prepared from three different polyurethanes with different acrylic content is presented and discussed.