无溶剂低黏度聚氨酯灌浆材料的制备研究

Preparation Study of Solvent-free and Low Viscosity Polyurethane Grouting Materials

基于灌浆材料等体积混合要求,制备了无溶剂的低黏度聚氨酯灌浆材料。灌浆材料性能测试结果显示:固化剂为高活性含活泼氢化合物的灌浆材料黏度低,早期力学强度高;异氰酸酯为液态MDI类单体的灌浆材料力学强度和黏结强度高,并具有一定的柔顺性;随低黏度酯类降黏剂用量提高,灌浆材料的黏度、力学强度和黏结强度下降,断裂伸长率无明显变化。优化后的聚氨酯灌浆材料黏度低于50 mPa·s,2 h拉伸强度和7 d拉伸强度分别在10 MPa和20 MPa以上,2 h抗压强度和7 d抗压强度分别在15 MPa和30 MPa以上,断裂伸长率在5%以上,湿黏结强度在2 MPa以上。同时,聚氨酯灌浆材料的可灌性好,可采用专用注浆设备长时间持续注浆,满足无砟轨道道床与路基层间离缝快速填充需求。

Based on equal volume mixing requirements for grouting materials solvent free and low viscosity polyurethane grouting materials were prepared and the performances were tested.The results reveal that grouting material prepared by highly active compounds containing active hydrogen has low viscosity and high mechanical strength at early stage.Grouting material prepared by liquid MDI not only has high mechanical strength and adhesive strength but also has a certain flexibility.As the amount of low viscosity ester viscosity reducer raises viscosity mechanical strength and adhesive strength decline while the elongation at break is stable.The viscosity of the optimized polyurethane grouting material is lower than 50 mP a s tensile strength for 2 h and tensile strength for 7 d are more than 10 MPa and 20 MPa respectively compressive strength for 2 h and compressive strength for 7 d are more than 15 MPa and 30 MPa respectively elongation at break is more than 5%and wet adhesive strength is more than 2 MPa.Polyurethane grouting material is easy to be grouted which could be continuously grouted with special grouting equipment for a long time so as to meet the needs of rapid repairs of seams between ballastless track bed and subgrade.