Processing method, properties and application of functionally graded polymer materials based on the mixtures of poorly compatible epoxy resins

Abstract

In this study, the method of manufacturing of functionally graded polymer materials based on the mixtures of poorly compatible epoxy resins is suggested. A novel processing method allowing to control the filler distribution across the section of graded materials depending on the operating conditions was developed. The essence of the method is self-settling of the blend consisting of two liquid epoxy resins with different viscosities and densities. Depending on mixing and injecting order the functional additive having antifriction, anti-adhesive or heat-protective properties can be distributed either homogenously or nonuniformly. In the latter case after curing the functionally graded material can be produced. Based on the formulations of poorly compatible phenol novolac epoxy resin NPPN-638 and active diluent triglycidyl phosphate (TGP), new functionally graded polymer materials with continuous change of composition and properties were developed. The functional additive (graphite, glass microspheres, polytetrafluoroethylene powder) concentrates in the top layer of the self-settled epoxy mixture while the bottom layer is enriched by TGP which possess advantaged adhesion to various substrates. As a result, antifriction, anti-adhesive, heat-protective and intumescent flame retardant coatings with improved performance were obtained.