Preparation of waterborne polyurethanes from natural oils

M. E. V. HORMAIZTEGUI; M. I. ARANGUREN; V. L. MUCCI

Santa Fe

Congreso; Congreso Internacional de Metalurgia y Materiales SAM-CONAMET / IBEROMAT 2014; 2014

Sociedad Argentina de Materiales

Polymers derived from renewable resources such as vegetable oils, cellulose and soy protein are receiving increasing attention in the academy and industry, as polymer materials friendly to the environment. Among these polymers, waterborne polyurethanes (waterborne-PU) offer the advantages of having a viscosity independent of molecular weight, no need for external emulsifiers, flexibility, good low-temperature performance and high strength, non-flammability, environmentally friendly and generally, with good adhesive properties. However, they have drawbacks such as poor surface properties, chemical resistance and thermal and mechanical stability. In this work, waterborne polyurethanes made from an environmentally friendly diol such a PCL was prepared to be compared with the products obtained from a bio- diol derived from castor oil. The synthesis of the waterborne-PU was carried out in a three-necked reactor, in which the polyol/diol with isophorone diisocyanate (IPDI) and dimethylol propionic acid (DMPA) were mixed, at 85°C for PCL and 100°C for the bio-based polyol, under N2 atmosphere. When the reaction is completed, the product was cooled at room temperature and triethylamine (TEA) was added to neutralize the carboxyl groups (equimolar to the DMPA). The final product was suspended in water in order to obtain a stable dispersion. The success of the reaction was assessed using FTIR where the decrease of the peak at 2270 cm-1 of the isocyanate was observed. Finally, solid PU films were prepared by casting from dispersions of known concentration