Preparation Of Modified Phosphate Adhesive And Its Compatibility With Inorganic Materials

The use of adhesives in coating,casting,and composite materials is widespread.The most common adhesives on the market are organic and inorganic adhesives.Because of the disadvantages of organic adhesives,more and more attention has been paid to inorganic adhesives.Among the rest,phosphate adhesive is one of the most potential inorganic adhesives that can be manufactured and processed.Phosphate adhesive is more and more favored by researchers.Because it has the advantages of low cost,simple preparation process,non-toxic and non-pollution.At the same time,it is difficult to achieve curing at room temperature and the curing time is relatively long.And there are few evaluation on the compatibility of phosphate adhesives.The objective of this dissertation is to construct a pure inorganic adhesive that cures at room temperature,has a quick cure time,and is compatible with inorganic substrates.Based on this,the idea of step by step curing is put forward.The three factors-modified based solution,curing agent,and adhesive compatibility are each individually examined.The following are the primary research findings:(1)The phosphate liquid was prepared by phosphoric acid and aluminum hydroxide.Three kinds of modified aluminum dihydrogen phosphate base liquid was prepared by adding chromium oxide,zinc oxide and titanium oxide as modifier.The effects of different modifiers and their dosage on the composition,viscosity and morphology of aluminum dihydrogen phosphate base liquid were studied.The results showed that three modified aluminum dihydrogen phosphate base liquid have been successfully prepared.Among them,chromic oxide modified aluminum dihydrogen phosphate base liquid color is green.When the content of modifier is 8%,the film surface of the modified aluminum dihydrogen phosphate base liquid is the flattest.Zinc oxide modified aluminum dihydrogen phosphate base liquid is transparent,while titanium oxide modified aluminum dihydrogen phosphate base liquid is white.When the modifier content of the above two modified aluminum dihydrogen phosphate base liquid reaches 4%,the surface of each film is also relatively flat.The viscosity of all modified aluminum dihydrogen phosphate base liquid showed an increasing trend with the increase of the content of the modifier.The polymerization degree of Al(H2PO4)3 is improved by the introduction of modifier.(2)Chromium oxide modified phosphate adhesives,zinc oxide modified phosphate adhesives and titanium oxide modified phosphate adhesives were prepared by modified aluminum dihydrogen phosphate base liquid with these curing agents Cr2O3,Al2O3,MgO,ZnO and TiO2.The effects of different modifier with their dosage and different curing agents on the composition,micromorphology and element distribution of modified aluminum dihydrogen phosphate base liquid and modified phosphate adhesives were studied.Besides,the changes in bonding strength and curing time of different types of phosphate adhesives when applied to ceramic materials were further studied.And the heat and water resistance properties were investigated.The results showed that the optimal amount of chromium oxide modifier in modified aluminum dihydrogen phosphate base liquid is 8%.By separately adding 7.5%chromium oxide,alumina and magnesium oxide could obtain a modified phosphate adhesive with optimal bonding strength.The maximum bonding strength is 1.22MPa,1.11 MPa and 0.73MPa,respectively.As well as the curing times were 8h,8h and 6h.The optimal amount of zinc oxide modifier in modified aluminum dihydrogen phosphate base liquid is 4%.By separately adding 7.5%zinc oxide,alumina and magnesium oxide could obtain a modified phosphate adhesive with optimal bonding strength.The maximum bonding strength is 1.36MPa、0.89MPa and 1.16MPa,respectively.As well as the curing times were 8h,8h and 6h.The optimal amount of titanium oxide modifier in modified aluminum dihydrogen phosphate base liquid is 4%.By separately adding 7.5%chromium oxide,alumina and magnesium oxide could obtain a modified titanium adhesive with optimal bonding strength.The maximum bonding strength is 1.18MPa,1.08MPa and 1.01MPa,respectively.As well as their curing times were 10h.However,the water resistance and heat resistance of all the modified phosphate adhesives were poor.Step by step curing is confirmed by the above test results.With the combined action of modifier and curing agents,it could be cured at the room temperature by step-by-step curing.It optimizes the curing process,,and shortens the curing time.(3)The compatibility of chromic oxide modified phosphate adhesives,zinc oxide modified phosphate adhesives and titanium oxide modified phosphate adhesives with three inorganic substrates(sandstone,granite,marble)was investigated.The air permeability and water permeability of the three modified phosphate adhesives and three inorganic substrates were compared respectively.The subsequent results of the bonding strength between the substrate analysis were combined to make a choice.The results showed that chromic oxide modified phosphate adhesive is suitable for granite,zinc oxide modified phosphate adhesive is suitable for sandstone,and titanium oxide modified phosphate adhesive is suitable for marble.