研究了无规共聚聚丙烯管（PPR管）在不同条件下与聚氨酯防水涂料、二甲苯稀释剂接触后的变化，测定PPR管的拉伸性能和热学性能，探讨聚氨酯防水涂料、二甲苯稀释剂对PPR管性能的影响。结果表明：聚氨酯防水涂料中小分子有机物和二甲苯稀释剂均渗透到PPR管中，降低PPR管的屈服强度和断裂伸长率。聚氨酯防水涂料中小分子有机物渗入PPR管分子链的空隙中，增大了分子链段间的体积，二甲苯稀释剂加快聚氨酯防水涂料中小分子有机物的渗透，PPR管溶胀更明显，力学强度损失增大。小分子有机物对PPR管的抗氧化性有不良影响。聚氨酯防水涂料与PPR直接接触时，聚氨酯防水涂料中小分子有机物会渗透到PPR管中，影响PPR管的力学性能和抗氧化性等性能。

The study investigated the changes in random copolymerized polypropylene pipe (PPR pipe) after contacting with polyurethane waterproof coatings and xylene diluents under different conditions. The tensile properties and thermal properties of PPR pipe were measured, and the impacts of polyurethane waterproof coatings and xylene diluents on the properties of PPR pipe were discussed. The results show that small organic molecules of polyurethane waterproof coatings and xylene diluents penetrate into the PPR pipes, reducing the yield strength and elongation at break of the PPR pipes. Small organic molecules from polyurethane waterproof coatings penetrate into the gaps between the molecular chain of the PPR pipe, increasing the volume between the molecular chain segments. The xylene diluent accelerates the penetration of small organic molecules from polyurethane waterproof coatings. The swelling of the PPR pipe is more obvious, and the loss of mechanical strength increases. The small organic molecules have an adverse effect on the oxidation resistance of PPR pipe. When the polyurethane waterproof coatings directly contact PPR, the small organic molecules from the polyurethane waterproof coatings will penetrate into the PPR pipe, affecting the mechanical properties and oxidation resistance of the PPR pipes.