Study Of Chemical And Biological Reinforcement Materials In The Conservation Of Waterlogged Wood Relics

Waterlogged wood relics need to be reinforced in time after being unearthed,otherwise the dry shrinkage and deformation in the process of dehydration and drying would damage the historical value of these cultural relics.Till now,a variety of chemical materials have been applied in the reinforcement and protection of waterlogged wood relics,but no comprehensive horizontal comparison has been reported yet.This experiment will compare the reinforcement efect of various chemical reinforcement materials,and select the best materials and composite formula.At the same time,the performance of the biological material bacterial cellulose to reinforce the waterlogged wood was studied.The bacterial cellulose was produced by the tea fungus.The biological and chemical methods were used to reinforce the waterlogged wood.In chemical reinforcement experiment,chemically degraded medical tongue depressors were used to simulate wood relics,while rice paper and aged raw lacquer piece was used to simulate paper relics and lacquerware relics.Seven kinds of chemical materials(trehalose,xylitol,chito-oligosaccharide,lactitol,glyoxal,glycerin,poly ethylene glycol)were used to reinforce the samples.Properties including anti-shrink efficacy,hygroscopicity,moisture retention,strength,color change,folding resistance and antimicrobial property were tested to evaluate the reinforcement effect of each material.Then the best material and its suitable concentration range could be elected.In compound formula reinforcement experiment,two kinds of chemical materials with different advantages were combined to form compound formula.The compound formula were used to reinforce wood samples and reinforcement effect of composite formula with different proportions was evaluated.Then the composite formula with the best effect could be elected.In the experiment of reinforcing waterlogged wood with biological combined chemical method,the reinforcement effect of biological material was evaluated separately first.The mixed reinforcement scheme and the successive reinforcement scheme were used to reinforce wood samples and reinforcement effect of two schemes was evaluated.Then the better scheme could be elected.Among the chemical materials in this study,xylitol has the best comprehensive performance,with the optimal concentration range of 40%to 60%(w/v).lactito and trehalose also have good reinforcement effect,and chito-oligosaccharide has the best antimicrobial property.The compound chemical formula of xylitol and chito-oligosaccharide with concentration higher than 0.5%(w/v)can effectively improve the antimicrobial property of wood samples with the premise of ensuring the reinforcement effect.The comprehensive effect of the tea fungus which produces bacterial cellulose to reinforce the waterlogged wood alone is not ideal but the bacterial cellulose can effectively cover the surface of the wood for surface reinforcement.When biological combined chemical method was used to reinforce the waterlogged wood,the effect of successive reinforcement scheme was more ideal.The wood samples were filled with chemical materials first and then reinforced by bacterial cellulose on the surface,and the strength of wood samples was significantly improved.