The Effect of HMMM Crosslinker on the Coating Properties of Chemoenzymatically Synthesized Aliphatic Urethane Oil
The polymers known as urethane oils3,4 include materials that incorporate the carbamate functional group as well as other functional groups. In the present article, castor oil5 is used as a hydroxyl group containing polyol and isophorone diisocyanate as polyfunctional diisocyanate. The hydroxyl functionality of castor oil has been widely utilized to synthesize urethane oils. Castor oil, being a non-drying oil, was enzymatically inter-esterified with linseed oil6 (dry oil) to facilitate the drying of oils. The inter-esterification product thus formed was used for the production of urethane oils.
The present paper illustrates the study of the role of HMMM on coating properties of these new urethane oils synthesized using chemoenzymatically modified castor oil. Lipase, (EC 3.1.1.3) a triglyceride hydrolyzing enzyme,7-9 was used in the synthesis of partial esters to avoid difficulties such as color darkening, incomplete reaction, or loss of ingredients caused by using chemical catalysts. These reactions can be operated at mild conditions and are less prone to side reactions, which make them attractive candidates to conduct inter-esterification reactions.10-12