Study On Reinforcement Of Paper Cultural Relics With Cellulose Solution

Paper is the main carrier of civilization.As time goes by,many precious paper materials such as calligraphy,paintings,books,archives,have been acidified and deteriorated.They need to be deacidified and protected urgently.The paper is composed of cellulose mainly,and using fibers to strengthen the paper will not change the structure of the paper.The physical dissolution of cellulose in a low-temperature NaOH/urea system provides the possibility of using cellulose itself to strengthen paper,but higher concentrations of NaOH will quickly corrode the paper.In order to reduce the risk,this study selected two systems of low concentration NaOH/urea and LiOH/urea to prepare cellulose solution to strengthen the deteriorated paper.After a period of immersion treatment,the cellulose in the reinforcement solution is deposited on the surface of the paper,which enhances the paper's mechanical strength,thereby extending the life of the paper.Because the cellulose solution is weakly alkaline,the reinforcement solution can deacidify the paper.Filter paper,old book paper and Xuan Paper were selected as the main experimental paper,and the cellulose solution was used for the treatment.In order to evaluate the effect of the reinforcement solution,the paper's mechanical properties,basic properties,anti-aging properties and apparent morphology,fiber structure were tested.Three different types of model paper,Bamboo Paper,newspaper and printing paper,were treated with the above two fiber solutions,and the applicability of two cellulose solutions was determined by comparison.The cellulose solution prepared by the low concentration NaOH/urea mixed solution was used to treat the filter paper and old book paper.With the goal of optimizing the mechanical strength of the paper,various factors affecting the strength of the paper were studied.Then the study found that the tensile strength,number of double folds and tearing strength of the filter paper and old book paper were improved significantly.In particular,old books'number of double folds had been increased by 11times.And the appearance,basic performance and fiber structure of the treated paper did not change.After the treatment with the strengthening solution,a part of the acid in the paper was neutralized and a certain amount of alkali residue was formed.Therefore,the anti-acidification ability of paper was significantly improved.At the same time,the anti-aging ability of the reinforced paper has also been enhanced.This method realizes the integration of paper deacidification and reinforcement,and reduces the experimental risk and the difficulty of operation.For the first time,it was proposed to use cellulose solution prepared by LiOH/urea system to strengthen deteriorated paper.After treating the filter paper and Xuan Paper with the reinforcement solution,their mechanical properties were significantly improved.In particular,the tensile strength of Xuan Paper increased significantly from0.792 k N·m^-1 of original paper to 1.344 k N·m^-1.And Xuan Paper's number of double folds increased obviously from 16 times to 392 times.And After 3 days of thermal aging treatment,the mechanical properties of filter paper and Xuan Paper remained at a high level.This showed that after treatment by the reinforcement solution,the anti-aging properties of paper had also been improved significantly.After reinforcement,the acidity and alkalinity of the paper became alkaline,and the paper's resistance to acidification was also enhanced obviously.After reinforcement,the glossiness,brightness and appearance of the paper were basically unchanged,and the fiber structure and cellulose crystal form were also the same as the original paper.This method is easy to operate and has low risk.Bamboo Paper,newspaper and printing paper were selected as the experimental paper to evaluate the applicability of the above two cellulose solutions on different papers.By comparing the mechanical properties,anti-aging properties and apparent properties of the paper after treatment,it was found that the cellulose solution prepared by the NaOH/urea mixture was more suitable for newspaper reinforcement.Due to the newspaper is more fragile,so the lower the alkalinity of the reinforcement solution had the better effect.Bamboo Paper and printing paper are more suitable for strengthening with cellulose solution,which prepared by LiOH/urea system.Especially for Bamboo Paper,its tensile strength and number of double folds have been greatly improved from1.065 k N·m^-1 and 18 times to 1.844 k N·m^-1 and 281 times,the anti-aging properties of paper are also greatly improved.After the treatment with two kinds of reinforcement solutions,the ink and pigment on the experimental paper remained basically intact,and the apparent performance and fiber structure of the paper were basically unchanged.Both NaOH/urea and LiOH/urea systems can be used to prepare cellulose solution for deacidification and reinforcement of experimental paper,and realized the use of fiber itself to reinforce paper.The researched reinforcement treatment method has low risk,is easy to operate,and has good applicability.