Research On Inorganic Compatible Adhesives For Inorganic Cultural Relics

Cultural relic is the symbol of wisdom and civilization of a country,which recorded the details of ancestors in an era,and is an epitome of five-thousand splendid culture in China.Cultural relics are non-renewable resource,which have important historic and cultural value,therefore,it is a significant mission to complete the protection and restoration work of cultural relics.Aimed the stone cultural relics and pottery cultural relics especially the large unmovable grotto temple,stone carving,etc.inorganic cultural relics appear broken,ruptured,even fragment under the destruction of natural weathering and accident human factor.If this situation goes as it is,these cultural relics will disappear gradually in the future.Therefore,it is a vital task to develop high-performance bonding materials.At the dawn of cultural protection and rapid development period of organic synthetic polymer,a vast number of organic materials were used in cultural preservation.After several decades,the negative effect of organic materials are increasingly prominent.With the conception of material compatibility was put forward,the idea of using inorganic materials to protect inorganic cultural relics was widely recognized by conservators.In order to develop an eco-friendly,durable,high bonding strength and compatible with noumenon adhesive for broken cultural relics,this article will be discussed from the following five aspects:1.Before studying the adhesive systematically,through referring to references to acquire protection conceptions,demand for conservation materials as well as the assessment tests after adhesive was developed.Finally,designing research ideas.2.Research on diseases of inorganic cultural relics and analysis of fracture reasons.Analysis some representative samples:red pottery unearthed from Banpo and gray pottery of Han figurines of warriors and horses unearthed from Yangjiawan in Xianyang as well as sandstone samples of Thousand-buddha Grottoes in Guangyuan,Sichuan and Yungang Grottoes in Datong,Shanxi.The tests include elemental analysis,crystal structure analysis and microtopography analysis to analyze the broken reasons of stone and pottery relics to get the basic information of cultural relics.According to the above data combined with experience and related literatures,it is speculated that the reasons for the breakage of inorganic cultural relics are that the ceramic relics are low in self-sintering temperature,buried in the underground with high saltiness,loose in texture,brittle and easily broken and the stone cultural relics exposed outdoors are exposed to severe conditions.The influence of temperature and humidity produces micro-fissures,and with the recurrence of the situation,large cracks occur.However,the main reasons for the breakage of inorganic cultural relics are the destruction of natural disasters and human factors.3.The H2O-H3PO4 and Al(OH)3-H3PO4 basic adhesive system were studied through bonding strength,SEM,XRD,TG.From the results we can conclude that Al(OH)3-H3PO4 system has solidification at room temperature,good performance in tolerating high temperature and higher bonding strength than H2O-H3PO4 system.Meanwhile,adhesive exist structure defect and color alteration with cultural relics noumenon,Therefore,need to improve properties of adhesive.Results of adding filler in adhesive suggest that nano-ZnO can improve bonding strength but can't change color;TiO2 can change color but improve bonding strength limited and nano-TiO2 can not only improve bonding strength but also change color,which is an ideal filler.Finally,preparing adhesive according to the best formulation to test properties such as anti-salt property and resistance of high-low temperature property,and results indicate that inorganic modified phosphate adhesive can keep high bonding strength under destruction of soluble salt and high-low temperature.4.The research compared inorganic modified phosphate adhesive with epoxy which is commonest in cultural relics conservation currently in performance.From bonding strength,epoxy has higher strength than inorganic adhesive,but some of the organic adhesives have higher bonding strength than the object of protection,which can't meet the demand of bonding strength can't above the object of protection strength.Damp heat aging,heat aging,U-V lamp aging and freeze drying aging to test the tensile lap-shear strength,weight variation rate,color alteration and microtopography variation results conclude that epoxy resins have poorer aging resistance ability than inorganic modified phosphate adhesive.Results of thermogravimetric loss rate,breathability,water permeability and SEM reveal that the properties of inorganic modified phosphate adhesive more close to the cultural relics noumenon and more compatible with cultural relics.5.Application of inorganic phosphate adhesive in repair engineerings.The adhesive was used to repair the figurines of warriors and horses in Xianyang repository museum,Thousand-buddha Grottoes in Guangyuan and Yungang Grottoes in Datong.After repair,we received a good remediation effect through longitudinal survey.