Zhang Canlin, Yu Jianying, Xue Lihui, Sun Yubin
State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China.
Centrer for Materials Research and Analysis, Wuhan University of Technology, Wuhan 430070, China.
Materials (Basel). 2017 Jan 19;10(1):78. doi: 10.3390/ma10010078.
γ-(2,3-Epoxypropoxy)propyltrimethoxy silane surface modified layered double hydroxides (KH560-LDHs) were prepared and used to improve the ultraviolet ageing resistance of asphalt. The results of X-ray photoelectron spectrometry (XPS) indicated that KH560 has been successfully grafted onto the surface of LDHs. The agglomeration of LDHs particles notably reduced after KH560 surface modification according to scanning electron microscopy (SEM), which implied that the KH560 surface modification was helpful to promote the dispersibility of LDHs in asphalt. Then, the influence of KH560-LDHs and LDHs on the physical and rheological properties of asphalt before and after UV ageing was thoroughly investigated. The storage stability test showed that the difference in softening point (Δ) of LDHs modified asphalt decreased from 0.6 °C to 0.2 °C at an LDHs content of 1% after KH560 surface modification, and the tendency became more pronounced with the increase of LDH content, indicating that KH560 surface modification could improve the stability of LDHs in asphalt. After UV ageing, the viscous modulus () of asphalt significantly reduced, and correspondingly, the elastic modulus () and rutting factor (*/sin δ) rapidly increased. Moreover, the asphaltene increased and the amount of "bee-like" structures of the asphalt decreased. Compared with LDHs, KH560-LDHs obviously restrained performance deterioration of the asphalt, and helped to relieve the variation of the chemical compositions and morphology of asphalt, which suggested that the improvement of KH560-LDHs on UV ageing resistance of asphalt was superior to LDHs.
制备了γ-(2,3-环氧丙氧基)丙基三甲氧基硅烷表面改性的层状双氢氧化物(KH560-LDHs)，并将其用于提高沥青的抗紫外线老化性能。X射线光电子能谱(XPS)结果表明，KH560已成功接枝到LDHs表面。扫描电子显微镜(SEM)显示，KH560表面改性后，LDHs颗粒的团聚明显减少，这意味着KH560表面改性有助于促进LDHs在沥青中的分散性。然后，深入研究了KH560-LDHs和LDHs对紫外线老化前后沥青物理和流变性能的影响。储存稳定性试验表明，在KH560表面改性后，当LDHs含量为1%时，LDHs改性沥青的软化点差(Δ)从0.6℃降至0.2℃，且随着LDHs含量的增加，这种趋势更加明显，表明KH560表面改性可以提高LDHs在沥青中的稳定性。紫外线老化后，沥青的粘性模量( )显著降低，相应地，弹性模量( )和车辙因子( */sin δ)迅速增加。此外，沥青质增加，沥青中“蜂状”结构的数量减少。与LDHs相比，KH560-LDHs明显抑制了沥青的性能劣化，并有助于缓解沥青化学成分和形态的变化，这表明KH560-LDHs对沥青抗紫外线老化性能的改善优于LDHs。
