末端交联准理想无规3, 3-二叠氮甲基氧丁环-四氢呋喃共聚醚弹性体应力应变特性

The stress stain behaviors of polymers are closely related to the aggregation evolution in the course of strain process, while the study on strain-induced crystallization is mainly focused on the field of homopolymers, polyesters and so on. In this paper, taking hydroxyl terminated 3, 3-diazidomethyloxetane(BAMO), tetrahydrofuran(THF) equal molar ratio quasi-ideal random copolyether of poly (3, 3-diazidomethyloxetane-co-tetrahydrofuran) (PBT) as a prepolymer, the end-crosslinked PBT elastomer was prepared by a carbmate reaction. The test results of mechanical properties show that, both the stress and strain of the elastomer can monotonously increase with the decreasing of temperature, which rise up to 16.2 MPa, 740% at -40℃ from 0.72 MPa, 72% at 60℃. Therein, the stresses and strains can sharply increase with the decreasing of temperature below -20℃. The analysis of the aggregation evolution of PBT elastomer demonstrated that, the crystallization of BAMO micro-blocks existing in PBT strands is inducted at strain of 320% at -40℃ because of the strand orientation in strain direction and decreasing configuration entropy, which can enforce the interaction among strands and improve the mechanical properties of PBT elastomers. Cyclic tensile tests with a constant strain show that, the stresses gradually decrease with increasing round times, and it strongly depends on the effective strand density of PBT elastomer before test.