严寒地区公路用聚氨酯灌缝胶的制备及性能研究

Study on Preparation and Properties of Polyurethane Sealant for Highway in Cold Area

采用二苯基甲烷二异氰酸酯(MDI-50)和聚四氢呋喃二醇(PTMEG)合成预聚体(A组分),将其与含1,4-丁二醇(BDO)和丙三醇的B组分反应,制备用于严寒地区公路裂缝处的双组分聚氨酯弹性体灌缝胶。通过聚氨酯弹性体拉伸强度、断裂伸长率和硬度等性能测试来评价聚氨酯灌缝胶在低温环境下的使用性能。结果表明:当PTMEG相对分子质量为2000、BDO与丙三醇摩尔比为19∶1、异氰酸酯指数为1.05时,制备的聚氨酯灌缝胶在-40℃的综合拉伸破坏伸长率和材料自身断裂伸长率分别为310%和380%,与混凝土粘结强度约为1.1 MPa,表现出最佳综合性能,能够较好地满足严寒地区公路裂缝修复的使用要求。

The prepolymer(component A)was synthesized by diphenylmethane diisocyanate(MDI-50)and polytetramethylene ether glycol(PTMEG),and the prepolymer reacted with component B containing 1,4-butanediol(BDO)and glycerol(GL).The polyurethane sealant was prepared for crack treatment of highway in cold area.The tensile strength,elongation at break and hardness were characterized to evaluate the performance of polyurethane sealant at low temperature.The results showed that the performance of the polyurethane sealant was optimal when the relative molecular mass of PTMEG was 2000,n BDO/n GL was 19∶1 and isocyanate index was 1.05.In addition,the comprehensive breaking elongation and the elongation breaking of the material at-40℃were 310%and 380%respectively,and the bond strength was about 1.1 MPa,which could meet the requirements of highway crack treatment in cold area.