Effects on properties of varying the cis/trans isomer distribution in polyurethane elastomers made with 1,4‐cyclohexane diisocyanate

Abstract Polyurethane elastomers have been made using 1,4‐cyclohexane diisocyanate (CHDI), 1,4‐butanediol (BDO) and a 2000 M n polyether diol soft segment. The cis/trans isomer distribution of the CHDI was varied between 23% and 100% trans . This variation in isomer distribution had significant effects on the polyurethane's thermal and physical properties. Decreasidng the trans CHDI content gives polyurethanes with lower hardness, lower thermal stability, higher Coefficient of Linear Thermal Expension (C.L.T.E.) values and decreased modulus values. Morphology studies showed good phase separation between the hard and soft segment blocks as well as a block copolymer morphology between the cis and trans CHDI/BDO blocks in the hard segment. The polyurethanes made were compared to polyurethanes made with MDI and H 12 MDI, the leading aromatic and aliphatic diisocyanates respectively.