In order to study the curing process of hydroxyl‐terminated polyether (HTPE) with different curing agents, aliphatic triisocyanate (N100) and toluene diisocyanate (TDI), the crosslink density (XLD) and chemical processes of the curing reactions have been investigated by low‐field NMR spectroscopy and FTIR spectroscopy, respectively, while the mechanical properties of those two cure systems were studied as well. The results show that, for either HTPE/N100 or HTPE/TDI, the higher curing temperature leads to the shorter curing time to reach stability of XLD, while the final XLD decreases by increasing the temperature. The XLD and tensile strength of HTPE/TDI are both lower than those of HTPE/N100, although curing reaction of the HTPE/TDI system is faster and more complete, as seen from FTIR spectra. Besides, the tensile strength of HTPE/N100 based propellant attains the maximum value of 0.64 MPa at NCO/OH ratio of 1.4, while the maximum XLD value of 6.5 10⁻⁵ mol⋅cm⁻³ was obtained at the same time. The XLD is well correlated in tensile strength with the variation of NCO/OH, that suggests regulation of XLD value may be an effective way to optimize the curing conditions for improving mechanical properties of HTPE/isocyanate‐based propellants.

中文翻译：

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不同异氰酸酯固化的端羟基聚醚的研究：固化过程和力学性能

为了研究使用不同固化剂，脂族三异氰酸酯（N100）和甲苯二异氰酸酯（TDI）的不同固化剂对羟基封端的聚醚（HTPE）的固化过程，通过低粘度研究了交联密度（XLD）和化学过程分别使用了NMR谱和FTIR谱，同时研究了这两种固化体系的机械性能。结果表明，对于HTPE / N100或HTPE / TDI，较高的固化温度导致较短的固化时间以达到XLD的稳定性，而最终的XLD随着温度的升高而降低。HTPE / TDI的XLD和拉伸强度均低于HTPE / N100，尽管从FTIR光谱来看，HTPE / TDI系统的固化反应更快，更完全。除了，同时获得 10 ^-5  mol·cm ^-3。XLD的拉伸强度与NCO / OH的变化密切相关，这表明XLD值的调节可能是优化固化条件以改善HTPE /异氰酸酯基推进剂机械性能的有效方法。