水泥嵌缝用聚氨酯密封胶

Investigation on cement joint polyurethane materials

在甲苯二异氰酸酯中加入脱水聚醚N210,约2h滴加完毕后,将油浴温度升高到(78±2)℃,继续反应2.5～3.0h,可制备水泥嵌缝用聚氨酯密封胶。结果表明,水泥嵌缝用聚氨酯密封胶的—NCO/—OH摩尔比的最佳值为1.30∶1.00;提高—NCO/—OH摩尔比,可使试样的拉伸强度增加,扯断伸长率降低,邵尔A型硬度增大。

Polyurethane was synthesized by reacting two kinds of polyether polyol that had two or three functionality and toluene diisocyanate. The effect of reaction time on isocyanate functional group content and hydroxy functional group content was studied. Polyurethane was confirmed by FTIR spectrum. The mechanical properties of polyurethane sealant were analyzed. It was shown that the optimum mixture ratio of isocyanatea functional group content and hydroxy functional group content during the course of the reaction was about 1.30∶1.00 (mole ratio).