Synthesis and characterisation of rigid polyurethanes based on hydroxyalkylated cardanol formaldehyde resin

Rigid polyurethanes have been synthesised using 4,4'-dicyclohexylmethane diisocyanate reacted with either hydroxyalkylated cardanol formaldehyde or hydroxyalkylated dimerised cardanol formaldehyde resins. These polyurethanes are crosslinked. Polyurethanes prepared from linear hydroxyalkylated cardanol formaldehyde resin have better thermal and mechanical properties than polyurethanes prepared from branched hydroxyalkylated resins. The polyurethanes prepared from hydroxyalkylated dimerised cardanol formaldehyde resins excel over the polyurethanes from hydroxyalkylated cardanol formaldehyde resins.