Polyester polyols and polyurethanes from ricinoleic acid

Received 12 August 2007; accepted 22 October 2007DOI 10.1002/app.27783Published online 23 January 2008 in Wiley InterScience (www.interscience.wiley.com).ABSTRACT: Triols of molecular weights (MWs) 1000–4000, suitable for flexible foams, were prepared by transes-terification of methyl esters of ricinoleic acid with trime-thylol propane. These polyols were noncrystallizing, rela-tively low-viscosity liquids. They were reacted with diphe-nylmethane diisocyanate (MDI) to obtain elastomershaving glass transition temperatures below 2608C. Poly-mer networks from high-MW polyols exhibited relativelyhigh sol fractions suggesting that some cyclization oc-curred during polyol preparation. The low Shore hardness,relatively low strength and modest elongation of the elas-tomers were attributed to the specific structure of polyrici-noleic chains and the presence of dangling chains, servingas plasticizers.