ASSESSMENT OF MECHANICAL AND THERMOMECHANICAL PROPERTIES OF EPOXY-BASALT COMPOSITES MODIFIED WITH HALOGEN-FREE INTUMESCENT FLAME RETARDANTS

This study aims to examine the effect of flame retardants (FRs) on the mechanical and thermomechanical properties of
epoxy composites reinforced with basalt fibers. To effectively modify fire behavior, it is usually necessary to introduce significant amounts of FRs, which raises many concerns due to the potential deterioration of other functional properties, including
mechanical performance. In this work, 30 wt.% halogen-free FRs, including a two-component FR (ammonium polyphosphate
with pentaerythritol) and melamine cyanurate, were introduced into the polymer matrix. The unmodified and intumescent
FR-modified epoxy resin composites reinforced with basalt fibers were subjected to static flexural test and thermomechanical
properties assessment. The research results were correlated with the analysis of changes in the chemical composition assessed
using Fourier transform infrared spectroscopy. As a result, the saturation of the reinforcing fabrics by the modified epoxy
resin was limited, which caused a different failure mechanism under static bending and impact test conditions. Both FR systems reduced the flammability of the modified epoxy laminates along with also acceptable deterioration of the mechanical
properties. The most beneficial effects considering the combination of all the analyzed features were noted for the
two-component FR system containing ammonium polyphosphate and pentaerythritol.