聚氨酯环氧改性沥青制备及性能研究

Research on Preparation and Properties of Polyurethane Epoxy Modified Asphalt

环氧树脂脆性强、柔韧性低导致环氧沥青抗裂性能差,为改善环氧沥青的低温性能,需进行增韧改性。通过自行合成的聚氨酯用于环氧树脂改性得到聚氨酯/环氧树脂复合材料,并将聚氨酯/环氧树脂复合材料用于沥青改性,通过微观测试和宏观试验确定了聚氨酯改性环氧的掺量及改性机理,评估了聚氨酯/环氧改性沥青的黏度特征、微观相态分析,通过其力学性能确定聚氨酯/环氧的最佳掺量。研究结果表明,聚氨酯中异氰酸酯基会与环氧中的羟基发生化学接枝,增加化学交联点,改善了环氧树脂的韧性,聚氨酯的最佳掺量为20%。黏度试验结果表明,不同聚氨酯环氧掺量改性沥青的黏度均随时间的延长会逐渐增加,聚氨酯环氧掺量越高,改性沥青其黏度增长越快。拉伸试验表明,当聚氨酯环氧的掺量为40%时,其力学性能优异,且均满足规范要求。

Epoxy resin has strong brittleness and low flexibility,resulting in poor crack resistance of epoxy asphalt.In order to improve the low-temperature performance of epoxy asphalt,toughening modification is required.In this paper,polyurethane/epoxy resin composite materials are obtained by using self-synthesized polyurethane for epoxy resin modification,and polyurethane/epoxy resin composite materials are used for asphalt modification.The dosage and modification mechanism of polyurethane modified epoxy are determined through microscopic and macroscopic tests.The viscosity characteristics and microscopic phase analysis of polyurethane/epoxy modified asphalt are evaluated,and the optimal dosage of polyurethane/epoxy is determined through its mechanical properties.The results show that the isocyanate group in polyurethane would chemically graft onto the hydroxyl group in epoxy,increasing the chemical crosslinking point,and improving the toughness of epoxy resin,and the optimal content of polyurethane is 20%.The viscosity test results show that the viscosity of modified asphalt with different polyurethane epoxy content gradually increases with time.The higher the polyurethane epoxy content,the faster the viscosity of modified asphalt increases.The tensile test shows that when the content of polyurethane epoxy is 40%,its mechanical properties areexcellent and meet the specification requirements.