有机修饰高岭土对SBS改性沥青防水卷材涂盖料性能影响

Effect of organic-modified kaolin on performance of SBS modified asphalt for waterproofing sheet

关键词:  高岭土  有机修饰  SBS改性沥青  防水卷材  物理性能  老化性能

Key words:  kaolin  organic modification  SBS modified asphalt  waterproofing sheet  physical performance  aging performance

摘要:

为改善SBS改性沥青防水卷材抗老化性能,本文分别采用γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)和异丙基三(二辛基焦磷酸酰氧基)钛酸酯(NDZ201)对高岭土进行有机修饰,制备了KH570有机修饰高岭土和NDZ201有机修饰高岭土,利用红外光谱(FT-IR)、X射线衍射(XRD)、接触角和扫描电镜(SEM)对有机修饰高岭土进行了测试表征,研究了高岭土和有机修饰高岭土对SBS改性沥青防水卷材涂盖料物理和老化性能的影响。XRD和FT-IR分析表明:KH570和NDZ201化学键接到高岭土表面,但未改变高岭土的层间距；接触角测试和SEM观察显示有机修饰使高岭土疏水性增强、团聚度降低。相比普通高岭土,有机修饰高岭土减小了热和紫外老化后的软化点增量、粘度老化指数和低温柔性降低量,增大了接缝剥离强度保留率。FT-IR分析表明,两种有机修饰高岭土均有效抑制了SBS改性沥青涂盖料老化后羰基指数和碳碳双键指数的减小,显著提高了涂盖料的抗老化性能。相比KH570有机修饰高岭土,NDZ201有机修饰高岭土对SBS改性沥青防水卷材的物理性能和抗老化性能具有更好的改善效果。

Abstract:

In order to improve the aging resistance of SBS modified asphalt waterproofing sheet,γ-methacryloxypropyl trimethoxysilane (KH570) and isopropyl tri (dioctyl pyrophosphoric acid acyloxy) titanate (NDZ201) were used to modify kaolin for preparing KH570 organically modified kaolin and NDZ201 organically modified kaolin. Respectively,organic modified kaolins were tested and characterized by X-ray diffraction spectrometer (XRD) and Fourier transform infrared spectrometer (FT-IR), contact angle, and scanning electron microscopy (SEM). The effects of organically modified kaolins on the physical and aging performance of styrene-butadiene-styrene copolymer (SBS) modified asphalt for waterproofing sheet were investigated. The results of XRD and FTIR showed that KH570 and NDZ201were connected to the surface of kaolin through chemical bond, without altering the interlayer spacing of kaolin. Contact angle testing and SEM observations indicated that organic modification enhanced the hydrophobicity of kaolin and reduced its aggregation degree. Compared with original kaolin, organically modified kaolins reduced softening point increment, viscosity aging index, and low-temperature flexibility reduction of SBS modified asphalt after thermal and ultraviolet aging, while increasing the retention rate of joint peel strength. FT-IR analysis revealed that organically modified kaolins effectively inhibited the increase of C[FY=,1]O content and the decrease of C[FY=,1]C double bond content of SBS modified asphalt after aging, thereby enhancing the aging resistance of the waterproofing sheet. Furthermore, compared with KH570 organically modified kaolin, NDZ201 organically modified kaolin exhibitssuperior improvements in the physical properties and aging resistance of SBS modified asphalt waterproofing sheet.