用于紫禁城清代建筑琉璃瓦保护的桥式硅氧烷的制备及性能研究

Synthesis and Properties of a Bridged Siloxane for Protection of Architectural Glazed Tiles of the Qing Dynasty in the Forbidden City

紫禁城清代建筑琉璃瓦是我国琉璃技艺的精华,但是部分现存的琉璃瓦却出现了变色、污染、开裂、风化、剥釉等损坏。本工作针对剥釉损坏,以异佛尔酮二异氰酸酯和3-氨基丙基三乙氧基硅烷为反应原料,设计合成了具有桥联结构的硅氧烷(BSQ),一种新型有机无机杂化材料,并将其用于琉璃瓦的保护。测试了保护后琉璃瓦的吸水率、接触角、色差、透气性、抗压强度等参数;并对保护后的琉璃瓦进行了耐化学侵蚀、耐冻融实验。结果表明,保护后的琉璃瓦具有较好的憎水性,强度得到提高,釉面剥落现象得到明显的抑制。

The architectural glazed tiles of the Qing dynasty in the Forbidden City are the most important glazed ceramic of China. But some serious deterioration such as color change, dirty, craze crack, efflorescence and glazed layer spallation are observed in some tiles. In this paper, a bridged siloxane （BSQ） protective material focusing on glazed layer spallation issue was designed and synthesized starting with isophorone diisocyanate （IPDI） and 3-aminopropyltriethoxysilane. Important properties including water absorption, contact angle, color change, water vapor diffusion and compressive strength of the treated glazed titles were examined. Furthermore, the chemical at-tack tests and freeze-thaw cycles were also evaluated. It shows that the BSQ treatment can modify the tile surface to hydrophobic, increase the strength of tile body and thus mitigate glazed layer spallation.