Influence of polyols on properties of bio-based polyurethanes

Polyurethane elastomers from cardanol-based polyol, polypropylene glycol (PPG-1200 and PPG-2000) and isophorone diisocyanate were prepared in the form of thin sheets. The sorption, mechanical and thermal properties were studied. The solubility parameter and molecular weight between crosslinks of polyurethane samples were calculated from swelling experiments. The swelling study of polyurethanes revealed that the sorption is found to decrease with an increase in chain length of PPG. The stress-strain data showed that the elastomers obtained using PPG-1200 gave the best mechanical properties. The thermal degradation of all the three elastomers starts almost at 270C, regardless of the PPG chain length. The value of activation energy of degradation calculated using the Broido method was in the range of 40-70 kJ/mol.