Table 12.4 Polymers of Commercial Importance Synthesis of Polyurethane氨纶，聚氨酯 H H N十c=0+o- OH H the urethane groups (-NH-(C-O)-O-)link the molecular units. Polyurethane fabricTable 12.4 Polymers of Commercial Importance / / Synthesis of Polyurethane 氨纶,聚氨酯 the urethane groups ( –NH–(C=O)–O– ) link the molecular units. Polyurethane fabric