The Effect of Castor Oil on the Structure and Properties of Polyurethane Elastohers (TDI System)

Segmented polyurethane elastomers, based on a mixture of castor oil and polypropylene glycol, toluene diisocyanate and 1,4-butanediol were prepared. The physical, thermal, dynamic mechanical behaviour, and x-ray diffraction have been studied. The use of castor oil shifts the main transition of the soft phase to higher temperature (glass transition temperature Tg increases), improves hardness, tensile strength, modulus and tear strength. Elongation and abrasion resistance decrease as ratio of castor oil increases. X- ray diffraction patterns show elastomers are amorphous. Trifunctionality of castor oil leads to the crosslinking of soft segments and a decrease of solubility and swelling of elastomers.