这可用脲键比氨酯键有较好的相分离和较高的熔化温度来说明。
The results can be explained in terms of better phase separation and higher melting temperatures of the urea linkages over the urethane linkages.
异氰酸酯的改性方法包括氨酯改性、二聚改性、三聚改性、缩二脲改性、碳化二亚胺改性和封闭改性等。
Methods for the modification of isocyanates include process of urethane, dimerization, trimerization, biuret, carbodiimide, and blocking reaction, etc.
本文用红外光谱法较系统地研究了聚醚型聚脲氨酯内的氢键及其性质，表明材料内的NH基团是几乎完全氢键化的。
The hydrogen bonds and their property of the polyether polyurethane-urea have been systematically studied. The results indicate that the NH groups are almost completely hydrogen-bonded.
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