一步法制备BAMO-THF型热塑性弹性体及其力学特性

以一缩二乙二醇(DEG)为扩链剂,通过一步熔融聚合法,制备得到高含量3,3-二叠氮甲基氧丁环与四氢呋喃共聚醚(BAMO-THF)型含能热塑性弹性体(ETPE)。采用傅里叶变换红外光谱(FT-IR)和广角X-射线衍射仪(WXRD)表征制备的ETPE结构,动态力学热分析(DMA)、万能材料试验机、邵氏硬度仪研究其力学性质。结果表明,制备的BAMO-THF型ETPE具有明显的叠氮型聚醚聚氨酯弹性体特征。在加载应力和温度作用下,由于其线性分子链结构,ETPE试样蠕变程度较大。此外,扩链剂含量的增加并不利于ETPE延伸率和低温性能的提高。其中软段BAMO-THF含量达到93.3%,硬段含量仅为6.7%的D20试样力学性能较佳,抗拉强度和断裂伸长率分别为3.61 MPa和1 277%,低温玻璃化转变温度为-23.4℃。

One-step preparation and mechanical properties of thermoplastic elastomer based on BAMO-THF

A series of energetic thermoplastic elastomer ( ETPE) were prepared by one-step melt polyaddition with high content of BAMO-THF. The structure of the ETPE was characterized by Fourier transform infrared spectroscopy ( FT-IR) and wide X-ray diffraction (WXRD). The mechanical properties were investigated by dynamic mechanic analysis (DMA), universal testing ma-chine, and shore durometer. The results reveal that the prepared ETPE based on BAMO-THF have typical features of azido-typed polyether-based polyurethane. Additionally, due to their liner structure, all the samples exhibit strong degree of creep under loading stress and test temperature. Moreover, the increases of chain extender prejudice the elongation and low-temperature mechanical properties significantly. Among all tested samples, the D20 exhibits satisfactory mechanical properties, where the desired soft seg-ment ( BAMO-THF) reaches 93.3% and hard segment decreases to 6.7%, and thereby its tensile strength reaches 3.61 MPa while elongation at break attains 1277% along with glass transition temperature Tg of -23.4 ℃.