核电站事故环境对环氧涂层理化性能的影响

Effects of Accident Conditions on Physicochemical Properties of Epoxy Coating in Nuclear Power Plant

以双酚A型环氧树脂和聚酰胺固化剂为主原料制备了环氧涂层,分别研究了核电站设计基准事故(DBA)和严重事故环境对其理化性能的影响。利用红外光谱(FTIR)对试验后的样品结构进行了对比分析,样品在辐照试验后检测出了苯醌结构的特征吸收峰。采用热重分析仪(TGA)测定了样品试验后的热稳定性参数。通过涂层附着力测试,评价了各试验对碳钢板与环氧涂层黏结强度的影响。结果表明:辐照试验产生苯醌是导致涂层黄变的主要原因;辐照和高温高压处理过程会导致环氧涂层的网络结构重排和断裂,对不同热稳定性参数的影响方向并不完全一致;湿热试验和DBA试验对涂层黏结强度影响较小,而辐照试验和严重事故则会显著降低涂层附着力。

The epoxy coating was prepared with bisphenol A-type epoxy resin and polyamide curing agent as main materials.The effects of nuclear power plant design basis accident(DBA)and severe accident environments on the physicochemical properties of the coating were studied respectively.Fourier transform infrared spectroscopy(FTIR)was used to compare and analyze the structure of the samples after test,and characteristic absorption peaks of benzoquinone structure were detected after irradiation test.Thermogravimetric analyzer(TGA)was used to determine the thermal stability parameters of the samples after test.Adhesion tests were executed to evaluate the adhesion strength between carbon steel plate and epoxy coating under various test conditions.Results show that the formation of benzoquinone during irradiation test is the main cause of coating yellowing.Irradiation and high temperature and pressure treatment can lead to the rearrangement and fracture of the network structure of the epoxy coating,with inconsistent effects on different thermal stability parameters.The damp heat test and DBA test have minimal effect on the adhesion strength of the coating,while irradiation test and serious accident conditions significantly reduce the coating adhesion strength.