RTV涂层染污后憎水性迁移影响因素的研究

Study of Influencing Factors on Polluted RTV Coatings Hydrophobicity Migration

研究室温硫化(room temperature vulcanization,RTV)硅橡胶涂层染污后憎水性迁移及其影响因素对RTV的应用具有指导意义。笔者以盐和灰的混合物模拟现场污秽,通过静态/动态接触角法表征憎水性,研究了迁移时间、温度、湿度、盐类型、灰类型、盐密、灰密对RTV涂层憎水性迁移速度的影响。结果表明:随着迁移时间的增加憎水性逐渐变好,迁移完全样本的接触角大于洁净样本;随温度增加迁移速度变快,且温度越高速度增加越快;随相对湿度增加迁移速度减慢,迁移所需时间非线性增大;ZnSO4迁移速度最快,NaNO3、NaCl、CaSO4相近;灰为硅藻土时污层的迁移速度快于高岭土的;随盐密/灰密(污秽度)的增加迁移速度有下降的趋势。

It is important to study polluted room temperature vulcanization（RTV） silicone rubber coatings hydrophobicity migration and its influencing factors,which has guiding significance to RTV application.In the paper,mixture of salt and ash was used to simulate on-site pollution,and static contact angle/dynamic contact angle method is used to express hydrophobicity of RTV coatings.The influence of hydrophobicity migration duration time,temperature,humidity,salt type,ash type,salt deposition density（SDD）,non-souble salt deposition density（NSDD） on RTV coatings hydrophobicity migration speed was studied.The result indicates that： hydrophobicity become well with the increase of migration duration time and the contact angle of migrated well sample will be larger than that of the clean one.Hydrophobicity migration speed becomes fast with the increase of temperature and the higher temperature the faster increasing speed.Hydrophobicity migration speed becomes slower and migration needed time nonlinear increases with the increase of relative humidity,and the higher relative humidity the longer migration time.ZnSO4 has the fastest migration speed,and NaNO3,NaCl and CaSO4 have close migration speed.Kieselguhr has faster migration speed than kaolin.The migration speed will decrease with the increase of SDD/NSDD（pollotion degree）.