Epoxy-based composites and coatings: improvement of multifunctional properties

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2019
Çaldıklıoğlu, Almira
The purposes of this study are to improve mechanical properties, thermal stability, resistance to flammability, electrical conductivity and hydrophobicity of epoxy (E) by incorporation of expanded graphite (EG) and titanium dioxide (T) particles. In this study, sonication with the use of solvent method was primarily determined for the epoxy-based binary composite and coating preparation. By this method, the epoxy composites and coatings were produced by changing EG concentration as 0.05, 0.1, 0.25, 0.5, 0.75 and 1 wt.% and changing TiO2 concentration as 0.5, 1, 2 and 5 wt.%. On the other hand, sonication with the use of solvent method was modified for fabrication of the epoxy-based hybrid composites and coatings, and their optimum formulations were determined based on the mechanical properties of the E/EG and E/T binary composites. The epoxy-based composites were characterized by tensile and impact tests, Shore D hardness test, SEM analysis, thermal analyses, LOI analysis and electrical resistivity test while water contact angle measurement and surface energy analysis were performed on their coatings. The tensile strength, elastic modulus and impact strength of the neat epoxy were increased by 24%, 25% and 40% over the neat epoxy at 0.1 wt.% EG loading while the electrical resistivity was reduced from 1014 to 109 ohm.cm at this concentration. The LOI value of the neat epoxy was increased to 26% by 5 wt.% TiO2 addition. The E/0.05EG/0.5T hybrid composite provided higher enhancement in tensile and impact properties compared to its binary composites.