Effect of the diisocyanate and chain extenders on the properties of the cross-linked polyetherurethane elastomers

Polyurethane elastomers with potential for applications in damping bearings were synthesized with 1,6-hexamethylene diisocyanate, 4,4'-methylenebis-(phenylisocyanate), poly(1,4-butane)diols (Terathane 1400), 1,4-butane diol 1,6-hexane diol and glycerin chain extenders. The glass-transition temperatures of the materials ranged from -42 to -75 C and were higher for polymers based on 4,4'-methylenebis-(phenylisocyanate) and with higher hard segment (HS) contents. The tensile strengths of the materials were 20-55 MPa and the tensile moduli were 30-134 MPa. These increased with increasing HS content. Interchain cross-linking improves thermal stability, which was measured by thermogravimetric analysis and differential scanning calorimetry. The structure and amount of HS used causes a significant variation in the properties of cross-linked elastomers.