LI Qijiang, WANG Xianlv, YUAN Feng, ZHANG Maolin, WU Jun

(Research Center of Ancient Ceramic, Jingdezhen Ceramic Institute, Jingdezhen 333001, Jiangxi, China)

Abstract: Aiming at the highest repair requirements for white porcelain body, ultra white kaolin was selected as the raw material of aluminosilicate, while sodium silicate and NaOH were used as the composite activators, alkali-activated gelling polymer materials that can be used for the repair of ancient ceramics have been prepared. The effects of calcination temperature, activator modulus, dosage of activator and water consumption on flexural strength and hydrolysis resistance of the samples were studied and discussed. Whiteness, transmittance, flexural strength of the bonded white ceramic body and shrinkage of the optimized samples were compared with those of gypsum, with their structural characteristics to be analyzed by using SEM and XRD. It was demonstrated that the nano spherical silica alumina gel polymer was formed through polymerization, without the presence of crystal or quasi crystal. Specifically, the optimized sample reached a flexural strength of 10.72 MPa and the highest hydrolysis resistance. The activation temperature of kaolin and water consumption had the stgrongest influence on the performance of the materials. The strengths of the porcelain body and pottery were 31.71 times and 5.29 times of gypsum, respectively. The whiteness and light transmittance of the optimal samples were similar to those of gypsum, but their expansion coefficient was higher than that of gypsum. This work broadened the application field of alkali-activated gelled polymer, which is of great significance to the restoration of ancient ceramics.

Key words: ancient ceramic; restoration; alkali-activated; inorganic gelling materials; Kaoli