| Epoxy resin (EP) with superior electrical insulation, chemical resistance andcohesiveness which determined by benzene rings and ether bond in structure is widelyused in the field of coating, adhesive and engineering material. EP adhesives can stickall sorts of metal and most nonmetal materials very well. EP need to be modified, sincebonding metals demands certain electrical conductivity. The toughening modificationis also necessary, since EP is very brittle. Multi-walled carbon nanotubes (MWNTs)with remarkable mechanical properties, thermal properties and electrical properties areideal filler of polymers. However the achievement of superior performance inMWNTs/EP composites is hindered by the fact that MWNTs tend to agglomerate andhave poorly disperse in EP matrices. In this research, raw MWNTs were treated withmixed acid. The dispersed way which the highly homogeneous dispersion of MWNTsin MWNTs/EP composites could be achieved was found. The influence of variousMWNTs content on properties of MWNTs/EP composites was investigated.The effects of various acid-treated method of MWNTs on disperse effect wereinvestigated. MWNTs which were treated for2h with heat and stir have the besteffects of purification and functionalization. The influence of curing conditions anddisperse methods (stir, dissolvant and emulsification) on properties of EP werediscussed. The optimal preparation conditions of composites were found out:emulsifying disperse methods and curing conditions of RT/2h+70℃/2h+125℃/2.5h+150℃/1h.Utilizing in situ polymerization, MWNTs/EP composites with different MWNTscontent was prepared. The study of morphology and properties shows certain contentof MWNTs can highly homogeneous dispersed in EP. Because of interface interactionbetween MWNTs and EP, the glass transition temperature (T_g), strength and toughness of MWNTs/EP composites are improved. Compared to the neat epoxy system,composites prepared with10wt%MWNTs showed20℃rise in T_gand nine ordersof magnitude reduce in volume resistivity. The percolation thresholds between4wt%and6wt%are observed. Compared to the neat epoxy system, composites preparedwith6wt%MWNTs showed with83%increase in tensile strength,83%increase inelastic modulus and89%increase in impact strength. |
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