选择3种涉水无规共聚聚丙烯（PPR）管材和3种聚氨酯防水涂料作为迁移试验样品，并确定了迁移试验的方案和试验用试件的制备方法。将所制备的试件置于烘箱中，在不同的温度下进行周期为14 d的迁移试验。在试验到达14 d时，立即抽取管外气体和管内气体各0.5 mL进行气相色谱-质谱法（GC-MS）分析；随即将预置在管内的吸附管取出进行热脱附-质谱分析；然后用乙酸乙酯20 mL反复冲洗PPR管，收集全部冲洗液进行GC-MS分析；最后，将冲洗过的PPR管沿内径中心切开，分别用乙醇和丙酮擦拭内外表面后置于环境舱中1 d后，采集舱内气体并进行热脱附-质谱分析。在上述各测试中，选择聚氨酯防水涂料中在50 ℃时就发生迁移且含量较高、分离较完全的3种甲苯类化合物（3-乙基甲苯、2-乙基甲苯和1，3，5-三甲苯）作为迁移参照物（MRPU）。试验结果表明：①检测的温度条件是决定材料之间迁移的决定性因素。当温度不小于50 ℃时，聚氨酯防水涂料中的化学成分能迁移至PPR管内；当温度不大于40 ℃时，则未发现有迁移发生，由此可确定聚氨酯防水涂料中化学组分发生迁移的临界温度为40~50 ℃。②3种PPR管在相同温度下迁移的结果完全相同，由此可知PPR管本身对迁移的影响很小，或者可说其影响远小于温度的影响。③如果PPR管经保护层处理，则聚氨酯防水涂料中的化学组分不能迁移至管内。

Three brands of PPR pipes used in water conveying and 3 brands of polyurethane waterproof coatings were selected as testing samples for the migration study. Procedures for preparation of specimen and for manipulation of the migration test were proposed. The test were carried out in a oven through a period of 14 d and at various temperature. At the end of the 14th day, 0.5 mL each of gas sample of EG and IG were taken and used for GC-MS analysis. The adsorption tube, which was placed preliminarily in the PPR pipe was taken out instantly in due succession and used for TD-MS analysis. The PPR pipe was then washed thoroughly with 20 mL of ethylacetate, which was collected and submitted for GC-MS analysis. And finally, the PPR pipe was cut into 2 pieces at its center along the inner diameter, and then the 2 pieces of the PPR pipe were cleaned inside and out with ethanol and acetone in succession, after which the PPR pipe pieces were cultivated for 1 d in the environmental cabin, and sample of gases in the cabin was collected and analyzed by TD-MS. In either of the above analysis, 3 toluenes (i.e., 3-ethyltoluene, 2-ethyltoluene and 1,3,5-trimethylbenzene) in polyurethane waterproof coatings were selected as reference compounds of the migration (MRPU) to be detected, because these 3 toluenes could be migrated at a relatively low temperature of 50 ℃ and these compounds gave high peak areas and showed well separation. It was found that ① testing temperature is the decisive influential factor to the migration of chemical components among the chemical materials. As shown by the results of this study, under temperature conditions of ≥50 ℃, chemical components in polyurethane coatings, happened to migrate to PPR pipes, while under temperatures ≤40 ℃, no such migration was observed. Hence, the critical migration temperature for the migration of chemical components from polyurethane is confined in 40 ℃ to 50 ℃. ② Same migration results were found among the 3 brands of PPR pipes under same testing temperature. Hence, it is recognized that PPR material itself gives only slight influence to the migration process or that the influence given by PPR material is much less those given by temperature. ③ If the PPR pipe was coated with protective layer preliminarily, the migration of chemical components from polyurethane coating to PPR pipes was completely blocked.