| Polymer repair materials have the advantages of good mechanical properties,good thermal stability and chemical stability,easy to operate,and can be cured at room temperature,which is a new material in asphalt pavement crack mending engineering.Bisphenol A type epoxy resin has the advantages of strong adhesion and excellent mechanical properties,and it also has the disadvantages of high brittleness,small fracture elongation,poor mechanical impact and thermal shock.Although the tensile strength of polyurethane material is not high,it has the advantages of high elasticity,wear resistance,fatigue resistance,strong impact resistance,good vibration resistance,etc.,and it can be very good with other kinds of polymers.Compatibility.Therefore,the use of PU modified EP not only will not weaken the effect of EP,but also transform its shortcomings to a certain degree of improvement.The aim of this paper is to study the best preparation process of interpenetrating polymer network,and the optimum toughening ratio was determined.Meanwhile the solidification reaction kinetics and polymer reaction mechanism of interpenetrating polymer network were studied in depth.In this paper,modified aliphatic amine was used as curing agent to modify the bisphenol A epoxy resin by polyurethane,and the interpenetrating polymer network road repair material was prepared.The viscosity of the prepared PU-EP IPNs was measured by viscometer to analyze the performance of road repair material.The research on interpenetrating polymer network thermal stability by thermogravimetric analysis by infrared spectroscopy;the structure analysis of interpenetrating polymer network system of polypropylene glycol and isocyanate,the reaction mechanism of PU modified epoxy resin reaction mechanism;by scanning electron microscopy of interpenetrating polymer network and internal tensile fracture analysis of compatibility and morphology of interpenetrating polymer network two polymer materials;thermal stability by differential scanning calorimetry interpenetrating polymer network,and to study the kinetics of curing reaction.The tensile strength,shear strength and bond strength of PU modified epoxy resin structural adhesives were measured by electronic universal testing machine.The results showed that: the best preparation process of interpenetrating polymer network repair material is hydroxyl and isocyanate material in PPG and MDI,and the mass ratio is 2.4:1,PU synthesis time is 2.5h,PU and EP mass ratio is 2.5h,and the time of synthesis is 0.Under these conditions interpenetrating polymer network repair material initial viscosity of 1.672Pa·s,operation time is 26 min,the gelation time is 39 min,the surface drying time is 54 min,the curing time is 63 min,the performance meets the requirements;the tensile strength is 15.32 Mpa,shear strength 4.1Mpa,drawing strength was 5.12 Mpa,elongation rate 61.36%,can meet the requirements of the use of repair materials on the mechanical properties of epoxy resin;hydroxyl-OH and-OH reaction of isocyanate-NCO and PPG obtained by infrared spectroscopy,generate carbamate groups PPG and MDI,the reaction time is too long,-NCO and water molecules in the MDI side reaction of polyurea;scanning electron microscopy found after joining the interpenetrating polymer network showed obvious two-phase structure,PU and E-51 have different degree of cross-linking to form interpenetrating polymer networks,improve the resistance to external load The ability of the PU content reaches 50%,the interface of interpenetrating polymer network repair material is not smooth,crack and the distribution characteristics of clutter,ductile fracture;thermal analysis showed the addition of PU leads to the decrease of heat resistance the properties of the material,and the content of PU increasing,heat resistance decreased more significantly. |
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