This paper is concerned with the synthesis of poly (ether-urethane) with pendant amino groups. The copolyether produced by ring opening copolymerization of tetrahydrofuran and epibromohydrin was treated with sodium az...This paper is concerned with the synthesis of poly (ether-urethane) with pendant amino groups. The copolyether produced by ring opening copolymerization of tetrahydrofuran and epibromohydrin was treated with sodium azide in dimethylformamide to form azido substituted copolyether. The poly (ether-urethane) made from it was subjected to reduction reaction to convert azido group to amino group. The stress-strain behavior and dynamic-mechanical properties of poly (ether-urethane) containing pendant amino groups were studied.展开更多
采用劈裂拉伸和三点弯曲法研究了 Bukit Timah 花岗岩的动态拉伸力学特性。实验结果表明,当加载速率每增加一个量级,用两种方法得到的花岗岩抗拉强度增加了10%;对于同种加载速率的花岗岩试样,由三点弯曲法得到的岩石抗拉强度约为劈裂拉...采用劈裂拉伸和三点弯曲法研究了 Bukit Timah 花岗岩的动态拉伸力学特性。实验结果表明,当加载速率每增加一个量级,用两种方法得到的花岗岩抗拉强度增加了10%;对于同种加载速率的花岗岩试样,由三点弯曲法得到的岩石抗拉强度约为劈裂拉伸法得到的2.5倍。与抗拉强度相比,实验得到的花岗岩弹性模量数据比较离散,但变化幅度不大。基于实验结果,对岩石拉伸力学机理进行了初步分析。展开更多
文摘This paper is concerned with the synthesis of poly (ether-urethane) with pendant amino groups. The copolyether produced by ring opening copolymerization of tetrahydrofuran and epibromohydrin was treated with sodium azide in dimethylformamide to form azido substituted copolyether. The poly (ether-urethane) made from it was subjected to reduction reaction to convert azido group to amino group. The stress-strain behavior and dynamic-mechanical properties of poly (ether-urethane) containing pendant amino groups were studied.
文摘采用劈裂拉伸和三点弯曲法研究了 Bukit Timah 花岗岩的动态拉伸力学特性。实验结果表明,当加载速率每增加一个量级,用两种方法得到的花岗岩抗拉强度增加了10%;对于同种加载速率的花岗岩试样,由三点弯曲法得到的岩石抗拉强度约为劈裂拉伸法得到的2.5倍。与抗拉强度相比,实验得到的花岗岩弹性模量数据比较离散,但变化幅度不大。基于实验结果,对岩石拉伸力学机理进行了初步分析。
