Impacts of colorants on mechanical properties of epoxy-based fiber composites

Abstract

Polymer composites are recently being deployed to buildings and vehicles that are required to meet both load-bearing properties and aesthetic needs. Since color is one of the most essential elements of a design, coloring of structural composites is drawing great attention. Despite various attempts of coloration of polymer composites, there is a lack of study on the impact of coloration on mechanical properties of polymer composites. Here, we investigate the influence of colorants (one pigment and three dyes) on mechanical properties of epoxy-based fiber composites. In this study, we found that incorporation of 0.1wt% pigment (Cinquasia (R) Magenta D4570) enhances mechanical strengths of epoxy-based fiber composites by 10 %, which might be attributed to enhanced Tg of epoxy resin matrix where pigment acts as a particle reinforcement. Among three dyes (disperse, acid, and reactive dyes), only disperse dye was dissolved in epoxy resin monomer, but mechanical strengths of resulting composites decreased as the disperse dye reduces Tg of epoxy resin matrix, acting like a plasticizer in the matrix. With epoxy-based fiber composites colored with the pigment, we finally suggest implication of coloration that can be applied to early diagnosis of flexure of colored composites.