Preparation And Application Of Berberine Modified Carboxymethyl Cellulose

Paper cultural relics are an important part of cultural heritage and record a large number of precious historical materials.However,due to improper preservation or long storage time,paper cultural relics may suffer from aging,oxidation,acidification,microbial degradation and other pathological changes.Microscopically,it manifests as the damage of paper fiber structure,and on a macroscopic point of view,it manifests as paper discoloration and irreversible decrease in mechanical properties.Therefore,the protection of paper cultural relics is of great significance to archives and museums.As a natural renewable biomass resource,cellulose has a structure similar to that of paper fiber and has good biocompatibility.Its derivative,carboxymethyl cellulose（CMC）,is water-soluble,biodegradable and inexpensive.Its hydroxyl group can bond with the hydroxyl group of paper fiber to form hydrogen bonds,improving the bond cooperation between paper fibers.In order to protect paper and solve the problem of bacterial resistance,in this paper,CMC was modified by berberine hydrochloride（BBR）and trimethoprimethidine（TMP）to prepare paper antibacterial agents with good biocompatibility and biodegradation,which not only retained their original advantages,but also gain good antibacterial properties to paper.Through the supplement of modified SiO₂and hydroxypropyl starch phosphate（HPDSP）,a new type of multifunctional protective liquid was developed for paper protection,and the paper properties were measured.The main research contents and conclusions are as follows:Berberinated carboxymethyl cellulose（DCMC-BBR）was prepared by Schiff base reaction using CMC and BBR as raw materials,and its structure was characterized by IR,XRD and TG.The preparation process was optimized by single factor experiment and response surface method,and the quadratic multiple regression equation was obtained with the product amount as the response value and the reaction temperature,p H and reactant dosage.The antibacterial activity of DCMC-BBR against Staphylococcus aureus and Escherichia coli was evaluated by disk AGAR diffusion method.Trimethoprimed carboxymethyl cellulose（TMP-DCMC）was prepared by schiff base reaction using CMC and BBR as raw materials.The appropriate technological conditions were determined by single factor experiment and response surface methodology.Using DCMC-TMP as substrate and modified berberine as graft monomer,berberine modified trimethyloxylated carboxymethyl cellulose（TMP-DCMC-BBR）was prepared by Schiff base reaction.Its structure was characterized by FT-IR,XRD and TG.The antibacterial properties of TMP-DCMC-BBR was evaluated by AGAR disk diffusion method.The MICs of TMP-DCMC-BBR against Staphylococcus aureus and Escherichia coli were 0.2 mg/m L.Nano KH-791-SiO₂was synthesized by KH-791 and TEOS.By studying the effects of different mass fractions of KH-791-SiO₂and HPDSP on the properties of paper,a suitable mass concentration range was found for treating paper.In order to improve the antibacterial activity of paper,multifunctional protective solution BBR-DCMC/KH-791-SiO₂/HPDSP and TMP-DCMC-BBR/KH-791-SiO₂/HPDSP were prepared on the basis of previous experiments.Two optimal formulations of multi-functional protective solution were found through orthogonal experiment and the results of measuring paper properties.After the paper is treated with the multi-functional protective solution,the paper has good mechanical properties.At the same time,the prepared multi-functional protective solution endows the paper with certain antibacterial properties,aging resistance and acid and alkali corrosion resistance.In addition,through the determination of optical performance,writing ink experiment,the microstructure and appearance,texture analysis,the paper thickness,and p H,it is found that liquid can not only reinforce the paper,and also gives the paper certain multifunctional and deacidification properties.And the ink experiment showed that the color and luster of the coated paper would not change,nor did the ink spread,and the paper kept its original appearance,in line with the principle of"repair the old as old".The complex solution has a certain reversibility,can absorb ultraviolet light,can make the paper from ultraviolet damage to a certain extent.