叔醇扩链的交联聚氨酯弹性体的结构和力学性能

Structures and mechanical properties of cross-linked polyurethane elastomers extended by tertiary alcohol

采用二苯基甲烷二异氰酸酯、六亚甲基二异氰酸酯三聚体、聚四氢呋喃醚二醇、2,5-二甲基-2,5-己二醇为原料制备了不同交联度的叔醇扩链聚氨酯弹性体,通过溶胀度测试、红外光谱、示差扫描量热分析等表征了其结构,研究了交联度对聚氨酯弹性体力学性能和热稳定性的影响,同时通过应力松弛和循环拉伸分析了其动态可逆性。结果表明,叔醇扩链所得交联聚氨酯弹性体具有较好的热稳定性,90~120℃时具有动态可逆性。随着交联度减小,聚氨酯弹性体的拉伸强度和断裂伸长率呈现不断增长趋势,这为交联聚氨酯的再利用提供了依据。

The polyurethane elastomers extended by tertiary alcohol with different cross-linking degrees were prepared using diphenylmethane diisocyanate,hexamethylene diisocyanate trimer,poly(tetramethene ether)glycol and 2,5-dimethyl-2,5-hexanediol as raw materials.The product structure was characterized and the effects of cross-linking degree on the mechanical properties and the thermal stability of polyurethane elastomer were studied by infrared spectroscopy,swelling degree test and differential scanning calorimetry.The dynamic reversibility of the product was analyzed by stress relaxation and cycle loading.The results showed that the polyurethane elastomers extended by tertiary alcohol had good thermal stability and had dynamic reversibility at 90-120℃.The tensile strength and the elongation at break of the polyurethane elastomer were increased with the decrease of cross-linking degree and this provided a basis for the reuse of cross-linked polyurethane.