Study On Polyurethane Ionomer Modified Asphalt And Its Synergistic Self-healing

Self-healing polymer materials have attracted extensive attention and been explored research due to their ability about crack repairing,which improving the reliability and life cycle of materials.This paper aims to modify asphalt with self-healing polymer to improve its self-healing ability by active reinforcement technology.A novelty self-healing polyurethane was prepared by Diels-Alder cross-linking reaction between dihydroxypropyl maleimide and functional furan prepolymer FA-ID which has synthesized by the reaction of furanmethanol and isophorone diisocyanate,meanwhile the introduction of dimethylolpropionic acid and zinc acetate were used to form a crosslinking structure.The potential reversibility and self-healing ability of synthetic polymers were studied by differential scanning calorimetry.The reversibility of DA bond was illustrated by the change of enthalpy energy,and the function of zinc ion bond was illustrated by the comparison of enthalpy energy.However,the self-healing ability of the material was observed by the thermal microscope at microscopic conditions.The introduction of zinc ions also leads to a better degree of microphase separation between the hard segment and the soft segment of polyurethane through atomic force microscope(AFM)analysis,thus making the better tensile strength.DA-Zn-PU polyurethane has excellent mechanical properties and the self-repairing rate is 97.8 %.The best tensile strength of DA-Zn-PU polyurethane sample is 28.45 MPa,the tensile strength after self-repair is 25.85 MPa,and the self-repair efficiency of tensile strength is 90.8%.Modified asphalt by changing the content of polyurethane ionomers which was formed by chain extension of 1,4-butanediol and N-dihydroxypropyl maleimide.The polyurethane ionomers dispersed into island structure equably in the asphalt phase through the characterization of polarized light microscope.With the increase of their respective additions,their softening points and viscosities gradually decrease while the penetration gradually increases 1% maleimide polyurethane ionomer modified asphalt has the highest softening point of 53.1 ?,viscosity of 1334 mpa·s Mpapenetration of 48.9(0.1mm),moreover maximizing its self-healing properties.