Zhai Jinxian, Zhao Hanpeng, Guo Xiaoyan, Li Xiaodong, Song Tinglu
School of Materials, Beijing Institute of Technology, Beijing 100081, China.
China Academy of Railway Sciences, Standards and Metrology Research Institute, Beijing 100081, China.
Polymers (Basel). 2020 Oct 28;12(11):2507. doi: 10.3390/polym12112507.
The relationship between temperature and the mechanical properties of an end cross-linked equal molar random copolyether elastomer of 3,3-bis(azidomethyl)oxetane and tetrahydrofuran (P(BAMO-r-THF)) was investigated. During this investigation, the performances of two P(BAMO-r-THF) elastomers with different thermal histories were compared at different temperatures. The elastomer as prepared at 20 °C (denoted as S0) exhibited semi-crystallization morphology. Wide angle X-ray diffraction analysis indicated that the crystal grains within elastomer S0 result from the crystallization of BAMO micro-blocks embedded in P(BAMO-r-THF) polymeric chains, and the crystallinity is temperature irreversible under static conditions. After undergoing a heating-cooling cycle, this elastomer became an amorphous elastomer (denoted as S1). Regarding mechanical properties, at 20 °C, break strains and stresses of 315 ± 22% and 0.46 ± 0.01 MPa were obtained for elastomer S0; corresponding values of 294 ± 6% and 0.32 ± 0.02 MPa were obtained for elastomer S1. At -40 °C, these strains and stresses simultaneously increased to 1085 ± 21% and 8.90 ± 0.72 MPa (S0) and 1181 ± 25% and 10.23 ± 0.44 MPa (S1), respectively, owing to the strain-induced crystallization of BAMO micro-blocks within the P(BAMO-r-THF) polymeric chains.
研究了温度与3,3-双(叠氮甲基)氧杂环丁烷和四氢呋喃的端交联等摩尔无规共聚醚弹性体(P(BAMO-r-THF))力学性能之间的关系。在该研究过程中，比较了两种具有不同热历史的P(BAMO-r-THF)弹性体在不同温度下的性能。在20℃制备的弹性体(记为S0)呈现半结晶形态。广角X射线衍射分析表明，弹性体S0中的晶粒是由嵌入P(BAMO-r-THF)聚合物链中的BAMO微嵌段结晶形成的，并且在静态条件下结晶度是不可逆的。经过加热-冷却循环后，该弹性体变成了无定形弹性体(记为S1)。关于力学性能，在20℃时，弹性体S0的断裂应变和应力分别为315±22%和0.46±0.01MPa；弹性体S1的相应值分别为294±6%和0.32±0.02MPa。在-40℃时，由于P(BAMO-r-THF)聚合物链中BAMO微嵌段的应变诱导结晶，这些应变和应力分别同时增加到1085±21%和8.90±0.72MPa(S0)以及1181±25%和10.23±0.44MPa(S1)。
