Study On Conservation Materials Of Silicon-based Polyurethane For Paper Relics

As an important historical and cultural heritage of China,paper cultural relics record a large amount of historical information.As time goes on,paper cultural relics are eroded and damaged by a variety of factors,resulting in mildew,embrittlement and damage.Therefore,it is important to protect the paper relics.In this paper,the polyurethane materials were modified with inorganic silicon and silicone,epoxy cyclohexane-epichlorohydrin respectively.The formulation of the composite reinforcement liquid was developed and the paper properties were determined.The research content and conclusions are as follows:Nano-SiO_2-based polyurethane was synthesized.Paper samples were tested with the tensile strength,folding endurance,tearing strength,whiteness and brightness.The morphology of the paper fiber was observed by optical microscope,atomic force microscope,infrared absorption spectrum and ultraviolet absorption spectrum of paper were determined by FT-IR and UV spectrophotometer.And anti-aging test,acid and alkali resistance test,anti-mildew and antibacterial experiment,handwriting ink experiments were carried out.The results showed that the synthesized nano-SiO₂-based polyurethane can effectively improve the mechanical properties of the paper sample while maintaining the original appearance of the paper.At the same time,the protective liquid of nano-SiO₂-based polyurethane can improve the anti-heat aging,acid and alkali resistance,antifungal of paper.It is an ideal protective liquid for paper cultural relic to delay the aging degradation and microbial erosion of the paper.The effect of mass fraction of silicone-based polyurethane on mechanical properties and appearance of the paper were studied.The results showed that the reinforcement liquid of silicone-based polyurethane has a good effect when the mass fraction is 15%.The effect of mass fraction of epoxycyclohexane-epoxychloropropane-based polyurethane on mechanical properties and appearance were investigated.The results showed that the reinforcement liquid of epoxycyclohexane-epichlorohydrin-based polyurethane has a good effect when the mass fraction is 15%.Through the single factor and orthogonal test,the formula of the composite reinforcement liquid was obtained:15%of nano-SiO₂-based polyurethane,15%of silicone-based polyurethane,and 10%of epoxycyclohexane-epoxychloropropane-based polyurethane.After the paper was conservated by composite reinforcement liquid,the tensile strength and folding endurance of paper were improved,especially the folding endurance.Surface tension,density,viscosity and conductivity are indispensable basic physical properties in chemical engineering design and process optimization,and they are intrinsically linked to the thermodynamic properties of the solution.Therefore,on the basis of composite reinforcement liquid,their physical properties were determined.The conclusions were as follows:（1）The measurement of surface tension:the surface tension of 10%⁵0%composite reinforcement liquid was measured at 283.15K³13.15 K.The relationship between surface tension and temperature were correlated and parameters of the model were calculated.The average relative deviation was less than 0.99%.（2）The measurement of density:the density of10%⁵0%composite reinforcement liquid was measured at 283.15 K³13.15 K.The relationship between density and temperature were correlated and the parameters of the equation were calculated.The average relative deviation of each system was less than 0.063%.（3）The measurement of viscosity:the viscosity of 10%⁴0%composite reinforcement liquid was determined between 283.15 K³13.15 K.The relationship between viscosity and temperature were correlated and the parameters of the equation were calculated.The average relative deviation was less than 6.3%.（4）The measurement of conductivity:the conductivity of 10%⁵0%composite reinforcement liquid was determined between 283.15 K³13.15 K.The corresponding molar conductivity was calculated.The relationship between molar conductivity and temperature was correlated with the Arrhenius equation and the parameters of the equation were calculateded.