Properties of polyurethane elastomers with different hard/soft segment ratio

Three polyurethane elastomers (PU) containing different hard/soft (h/s) segment ratios were prepared. The PUs were characterized using Gel Permeation Chromatography (GPC), DSC, Wide Angle X-ray Diffraction (WAXD), Dynamic Mechanical Thermal Analysis (DMTA), and Stress-controlled rheometry. The surface properties were evaluated from contact angle measurements. The PUs were used as raw materials for solvent-based adhesives, whose adhesion properties were measured from T-peel tests of solvent-wiped polyvinyl chloride (PVC)/polyurethane adhesive joints. The increase in the amount of his segment ratio affected the structure and morphology of the PUs, reducing the degree of phase separation and the extent of the secondary interactions between polymer chains. The his segment ratio determined the thermal, mechanical, rheological and adhesion properties of the PUs.