Castor oil (CO) is a vegetable oil that allows for multiple reactions in their hydroxyl functional groups. Ricinoleic acid (12-hidroxioleic acid) comprises about 90% of the fatty acids present while the remaining 10% are not hydroxylated. The aim of the present work was to obtain polyols from castor oil (CO) and diethanolamine (DEA), to improve the crosslinking degree of final products to be used in electronic circuits. The use of diethanolamine instead of triethanolamine in the polyurethane resin formulation is of special interest of companies, due to the difficulties in acquiring triethanolamine, which is controlled by the Brazilian Army. Chemical and NMR characterization showed that the polyol obtained had a hydroxyl number between 230 and 280 mgKOH/g. The kinetics of the polyaddition reaction from polyols and isophoronediisocyanate (IPDI) was evaluated employing rheological assays at 60 ºC. The polyurethane based on DEA had compatible properties with the commercial products obtained from triethanolamine (TEA).
Castor oil; diethanolamine; polyurethane; rheological properties; electrical properties; hardness
