Rigid Polyurethane Foam Obtained from Enzymatic Glycerolysis: Evaluation of the Influence of Lipase on Biopolyol Composition and Polymer Characteristics

In this study, the synthesis of biopolyols derived from castor oil and glycerol was performed by enzymatic glycerolysis in a solvent-free system applying the lipases: Novozym® 435 (N435), from Candida antarctica fraction B, immobilized on macroporous anionic resin, and Eversa® Transform 2.0, a soluble formulation from Thermomyces lanuginosus. The biopolyols presented different conversion into mono- and diacylglycerol (MAG and DAG) owing to regioselectivity of the lipases. The resulting biopolyols were employed for the synthesis of polyurethane foams using different amounts of chemical blowing agent (water). The NCO source employed was polymeric methylene diphenyl diisocyanate (pMDI). The foams were compared, and the results showed that the PU foams obtained by using the biopolyol from lipase N435 presented uniform pore size and more desirable mechanical characteristics. Although this has arisen, the results obtained by using the lipase Eversa® Transform 2.0 showed the possibility of applying a low-cost enzyme to obtain biopolyols and foams, and there may be a possibility of competition with chemical catalysts.