1999 Volume 72 Issue 2 Pages 82-88
Polyurethane elastomers (TPUs) were synthesized by reacting NCO-terminated poly (oxy- tetramethylene) glycol (PTMG: 2000) or Poly (oxypropyrene) glycol (PPG; 2000) with ethylene glycol (EG) as a chain extender, and then TPU blends were prepared to mix with PTMG-TPU and PPG-TPU. On the other hand, co-polyurethane elastomers were synthesized by reacting NCO- terminated prepolymer consisted of PTMG and PPG with EG.
Physical properties of TPU blends and co-TPU were studied by the measurements of thermal analysis (DSC), dynamic viscoelastic analysis and tensile properties at various conditions. The relationship between structures and tensile properties of TPUs were investigated on the basis of the results of them. Tensile properties of blends failed for lower compatibirity of PTMG-TPU and PPG-TPU. On the other hand, tensile properties of co-TPU at higher temperature were improved by the incorporation of a little amount of PPG to the soft segment of TPU. As the results of DSC and dynamic viscoelastic analysis, it was found that the incorporation of PPG contributed to the enhancement of tensile pro-perties through its improving effect on the mobility of chain molecule in soft segment.
