The influence of carbon fiber arrangement in phenol-formaldehyde resin on the thermal resistance of the composite - 1

The paper presents the results of research on the effect of fiber arrangement on the ablation properties of a phenol-formaldehyde-carbon composite. The resin undergoes pyrolytic changes, while carbon fibers are oxidized at high temperature. This composite is used in places exposed to high temperatures. It degrades under the influence of a high-density heat flux and under the influence of oxygen. The research presents the results of the effect an acetylene-oxygen flame on a phenol-formaldehyde-carbon composite based on ASTM E285-08 - Standard test method for oxyacetylene ablation testing of thermal insulation materials. The tests were performed on composites filled with various carbon fiber arrangements in phenol-formaldehyde resin. Based on the burning time, mass loss and material degradation depth, the mass, linear ablation and the insulation index in 10 s were determined. Images of the degraded structure were taken. Individual sample tests show significant differences in the ablation properties of the given composite groups. The average mass ablation value of the group that showed the highest ablation values ​​was 3.3 times higher compared to the lowest average mass ablation value of the sample group that showed the best ablation properties. In the case of linear ablation, this difference was 4.5 times.