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

Effect of Hard Segment Composition of 3,3-Diazidomethyloxetane-Tetrahydrofuran Copolyethers Elastomer on Its Mechanical Properties

为探索3,3-二叠氮甲基氧丁环-四氢呋喃共聚醚[Poly(BAMO-THF)]弹性体中硬段结构组成对力学性能的影响,以甲苯二异氰酸酯(TDI)为固化剂,调节扩链剂1,4-丁二醇(BDO)与交联剂三羟甲基丙烷(TMP)添加比制备了一系列固化参数与硬段含量不变、硬段组成不同的Poly(BAMO-THF)弹性体S1~S5。力学性能测试表明,随BDO含量增加、TMP含量下降,弹性体拉伸模量由S1的(0.83±0.05)MPa单调降至S5的(0.51±0.02)MPa,断裂延伸率由S1的526%±50%单调增至S5的950%±60%,拉伸强度维持恒定((2.52±0.39)MPa^(2.75±0.31)MPa)。溶胀测试表明,弹性体S1~S5平衡溶胀率随TMP含量下降呈单调上升,化学交联程度下降。低场核磁研究表明,弹性体S1~S5表观硬段含量随TMP含量下降呈单调上升。红外分析表明,随TMP含量下降弹性体中羰基与氨基氢键缔合程度增加,弹性体的物理交联程度提高。

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.