【摘要】 为解决聚脲反应高活性方面存在的问题,对二胺扩链剂进行了改性。以己二胺为原料,在冰乙酸和磷酸条件下一步合成得到白色针状晶体产品即新型位阻型扩链剂二乙酰己二胺。并用红外光谱、凯氏定氮法和1H-NMR对其结构进行了表征,确定了合成产物的化学结构。将它和端氨基聚醚和4,4’-二苯甲烷二异氰酸酯(MDI)通过二步溶液法合成新型聚脲,考察二胺扩链剂改性对聚脲性能的影响。当用二乙酰己二胺代替己二胺合成聚脲时,其凝胶时间由原来的11s增加到52s,且拉伸强度大大提高。更多还原

【Abstract】 In this paper, the modification amine chain extenders were prepared for prolonging gel time of spray polyurea elastomer. A new chain estender called diacetyl hexamethyene-diamine can be got as a white acicular crystal by synthesizing hexamethylene-diamine under having acetic acid and phosphoric. Its characterizations and structure were confirmed by kjeldahl nitrogen and infrared spectra and ~1H-NMR. Polyureas are synthesized using 4,4’-diphenyl diisocyanate and amine terminated poly (oxypropylene) with the new chain extender. The effects of chain extenders on characteristics of polyureas were studied. The gel time is greatly changed from 11s to 52s when diacetyl hexamethylene-diamine is used as chain extender instead of hexamethylene-diamine, and the tensile strength is also greatly increased.更多还原