Influence of coloring on the properties of epoxy binders and fiberglass rebar based on them

Abstract

At present, polymer composite materials are widely used in the construction and automotive industries, products for which must meet not only operational, but also aesthetic requirements. Since color is one of the most important design elements, much attention is paid to the coloring of structural composites. There is a fairly wide range of different methods for coloring polymer composites, but each method has both advantages and disadvantages. This article discusses two methods for coloring a hot amine-cured epoxy composition, which is used for the manufacture of composite fiberglass reinforcement: by adding pigment and organic dyes to the epoxy composition. It has been found that organic dyes dissolve in all components of the epoxy composition, but become colorless upon heat treatment. When adding an insoluble dispersed pigment, the color remains unchanged even after the thermal curing of the epoxy matrix. The addition of up to 0.5 mass parts of iron oxide pigment (“red FEPREN TP-303”) to the epoxy binder slightly reduces the mechanical strength of the composite and significantly increases its thermal stability.