Study on the Gel Cleaning System for Removal of Poly (vinyl acetate) Fixative of the Mural Paintings of the Payathonzu Temple in Bagan, Myanmar (I) - Focusing on Properties and Removability of Gel Cleaners -

Abstract

In the past, PVAc [poly(vinyl acetate)] was used as a fixative for the conservation of the murals in the murals of the Payathonzu temple located in Bagan, Myanmar. In this study, attention was paid to gel cleaning as a method for stably removing such PVAc fixatives. Based on the recent research trend related to the cleaning of murals in Bagan ruins, 3 types of gelling agents (Nevek®, Laponite®RD, Carbopol®980) and 2 types of organic solvents (Acetone, Dimethyl carbonate) were selected. Six types of gel cleaners were prepared by mixing gelling agents and organic solvents, and the properties and fixative removability of these cleaners were compared. As a result of confirming the properties of the prepared gel cleaners, the pH of the cleaners was all in the weak acidic to weakly alkaline range, which was a stable condition for mural application. Also, there was no difference in the viscosity of the cleaners depending on the type of solvent, but there was a difference depending on the type of gelling agent used. Regarding the weight loss ratio of PVAc, which is an indicator of removability, the exposure conditions of the gel cleaners, the boiling point of the solvent used, and the viscosity of the gelling agent acted as factors affecting. As a result of comparing the removability of gel cleaners, it was confirmed that the solvent’s fixative solubility, the volatility of the solvent itself, and the solvent release control properties of the gelling agent had a great effect on the removability of the gel cleaners. In Part 2, the stability and the running applicability of the gel cleaners will be investigated by making mockup samples reflecting the properties of the materials and techniques used to produce the mural paintings in the Payathonzu Temple.

Study on the Gel Cleaning System for Removal of Poly(Vinyl Acetate) Fixative of the Mural Paintings of the Payathonzu temple in Bagan, Myanmar (Ⅱ) : Focusing on Applicability of Gel Cleaners

“…The same gel cleaners used in the previous Part 1 of the study were used in this study (Yu et al, 2021). 6 types of gel cleaners (NA, LA, CA, ND, LD, CD) were prepared by mixing 3 gelling agents (N: Nevek ® , L: Laponite ® RD, and C: Carbopol ® 980) and 2 organic solvents (A: Acetone, and D: Dimethyl carbonate) (Table 2, Figure 3).…”