Nano calcium hydroxide based organic gel for removing polyacrylic resin on mural surface and preparation method thereof

Abstract

The invention relates to a nano calcium hydroxide based organic gel for removing polyacrylic resin on a mural surface and a preparation method thereof. The preparation method comprises the following steps: adding nano calcium hydroxide and epoxy resin into an ethyl acetate solution, performing stirring and standing for 12-24h to prepare polyacrylic resin cleaning gel. The preparation method is extremely simple, time-saving, free of heating and low in cost. In the preparation process, nano calcium hydroxide reacts with ethyl acetate to generate calcium acetate serving as a cross-linking agent so as to promote gel formation. Calcium acetate is non-toxic and is a food preservative, so that the safety of the gel is greatly improved. Experiments for removing the polyacrylic resin polymer on themural surface show that the removal rate can reach 95% or above. In addition, according to the amount of polyacrylic resin on the mural surface, the percentage content of ethyl acetate can be flexibly adjusted from 70% to 85%, so that an optimal cleaning effect is achieved. The gel has excellent industrial production prospects and can be popularized to cleaning of high-molecular polymers on the surfaces of other cultural relics like stone and paper cultural relics.

Description

technical field [0001] The invention belongs to the technical field of ancient mural protection materials, and relates to an organogel for cleaning polyacrylic resin on the surface of murals based on nanometer calcium hydroxide and a preparation method thereof. Background technique [0002] Polyacrylic resin is an organic polymer protective material for murals that is widely used at home and abroad. The material has many advantages such as strong adhesion, simple construction, and little influence on the color of murals (Central Plains Cultural Relics, 2004, 01, 81-86), and it has been shown in the restoration and protection of murals in Dunhuang, India, Italy and other countries. good effect. However, the material is easy to age, turn yellow and become brittle, resulting in mechanical degradation or even failure; after a long time, it needs secondary reinforcement, and the aged material will have a great negative impact on the secondary reinforcement, so it needs to be rem...

AI Technical Summary

Problems solved by technology

[0003] At present, there are several methods of removal: (1) use a cotton swab dipped in ethyl acetate to wipe, this method is extremely inefficient and ineffective, and must be careful so as not to affect the mural; (2) use microemulsion, microemulsion The emulsion contains a cleaning agent such as ethyl acetate. Experiments have proved that the microemulsion has an excellent cleaning effect on polyacrylic resin and high efficiency. However, this system contains a large amount of water and surfactants, which are very easy to cause damage to murals (Adv.Colloid. Interface Sci.2014, 205, 361-371); (3) organogel, the preparation principle is to use cross-linking agent to connect polymers to form a network structure, and coat the cleaning agent in the network while the gel is formed. Gel preparation does not use water and surfactant, good cleaning effect, high removal rate (more than 80%), but the preparation is very complicated, time-consuming, both inert gas and heating are required, and the preparation process also needs repeated cleaning (each It takes 24 hours for the first cleaning), and it takes at least 4-5 days to successfully prepare the cleaning gel. In addition, the cleaning agent content in the gel can only be calculated by the final gel product and cannot be adjusted in advance. More importantly, the preparation of the gel The cross-linking agent used in the glue is highly toxic (Appl. Phys. A2015, 121, 857-868)