3, 3-二(叠氮甲基)氧丁环与四氢呋喃共聚醚弹性体硬段结构组成对其力学性能影响

In order to explore the effect of hard segment composition of 3, 3-diazidomethyloxetane-tetrahydrofuran copolyethers (poly (BAMO-THF))polyurethane elastomer on its mechanical properties, using toluene diisocyanate (TDI) as curing agent, a series of poly (BAMO-THF) polyurethane elastomers S1~S5 with the same curing parameters, the same hard segment content and different compositions of hard segment were prepared by adjusting the addition ratio of the chain extender 1, 4-butanediol (BDO) and cross-linking agent trimethylolpropane (TMP). The mechanical properties test shows that, with the increase of BDO content and the decrease of TMP content, the tensile modulus of poly (BAMO-THF) polyurethane elastomers decrease monotonously from (0.83 ±0.05) MPa of S1 to (0.51±0.02) MPa of S5, the elongation at break increases monotonously from 526%±50% of S1 to 950%±60% of S5, and the tensile strength at break remains almost constant (2.52 ±0.39) MPa~(2.75±0.31) MPa. Swelling test shows that the equilibrium swelling ratio of elastomers S1~S5 is increased monotonously with the decrease of TMP content, and the degree of chemical crosslinking is decreased gradually. Low field NMR reveals that the apparent hard segment content of elastomers S1~S5 increases monotonously with the decrease of TMP content. FT-IR analysis indicates that the degree of association of carbonyl and amino hydrogen bonds in poly (BAMO-THF) elastomers increases gradually with the decrease of crosslinking agent content, which increases the degree of physical crosslinking of the elastomers.