PROPERTIES OF WATERBORNE POLYURETHANE ADHESIVES WITH DIFFERENT HARD SEGMENTS CONTENT

摘要

A decrease in the NCO/OH ratio of the PUD produced: 1. an increase in the average particle size due to an increase in prepolymer viscosity. 2. a decrease in the molecular weight of the polyurethanes due to an increase in the average particle size. 3. polyurethane ionomers with lower thermal resistance (lower elastic moduli and cross-over temperature between moduli). 4. an increase in the thermal degradation stability due to the higher soft segment content. 5. an increase in the polyurethane crystallinity. 6. an improvement in the immediate and final adhesive strength to PVC.