Preparation And Properties Of Vitrimer Epoxy Asphalt Materials

Epoxy asphalt has good mechanical properties,strong bonding ability,little influence by climate and temperature changes and other factors.Its actual application scenarios are mainly steel bridge deck pavement,airport,tunnel,buliding seepage and waterproof and other important and special occasions.However,in the process of use,due to external effects such as temperature change and loading during use,defects such as cracks,looseness and pits may appear,which will affect the service life and performance of epoxy asphalt.Vitrimer material is a kind of new material with reversible covalent bond crosslinking network,which can be self-healing and repeatedly processed.This paper attempts to prepare a self-repair,renewable vitrimer epoxy asphalt,so as to extend the service life of epoxy asphalt.Therefore,the paper firstly improved the compatibility of matrix asphalt and epoxy resin by adding different reagents,and then introduces a variety of dynamic covalent bonds into thermosetting epoxy asphalt to obtain vitrimer epoxy asphalt.Finally,the self-healing remodeling property of vitrimer epoxy asphalt and the reprocessability of its mixture were studied.The main research contents and results are as follows:（i）In order to study the modification effect of cashew phenol,bismaleimide and maleic anhydride on asphalt by using the characterization methods of FTIR,XRD,SEM,FLM（fluorescence microtest）,tensile test,penetration and softening point,the curing principle of curing agent and catalytic mechanism of catalyst were explored.The vitrimer epoxy asphalt provides the basis for the construction of covalent bonds in different networks.The results show that excellent performance of vitrimer epoxy asphalt can be obtained by adding polyether polyols and maleic anhydride modified asphalt for esterification.（ii）Vitrimer epoxy asphalt materials with different dynamic covalent bonds were prepared.The relationship between the structure and properties of transestere-exchange reversible covalent bond network,disulfous reversible covalent bond network and multiple reversible covalent bond network was studied by using FTIR,TGA,DSC,BBR,DMA,SEM,tensile test and chemical solvent soaking.The results show that the sample with transesteric reversible covalency bond network has excellent properties,T_0.05 and T_i are 350℃and 260℃respectively,the tensile ratio before and after the first/cycle is higher than 320%,the recovery rate of cyclic tensile strength is 98.9%,and the sample shows good self-healing when heated at 100℃for 5min.（iii）By using FTIR,TGA,DSC,DSR and Marshall test piece remodeling methods,the effects of zinc acetoacetone,zinc acetate and compound catalysis on topological rearrangement mechanism and performance of vitrimer epoxy asphalt were studied.It was found that 1 wt.%zinc acetate only has good catalytic performance.Moreover,it is beneficial to the preparation process of vitrimer epoxy asphalt.