Structural and Chemical Features of Epoxy Composites Filled with Biogenic Lignocellulosic Filler Obtained from Agro-Industrial Waste

The work investigated the effect of organic biogenic microdispersed lignocellulosic filler on the physical, mechanical and thermophysical properties of epoxy composites. Attention is paid to the analysis of structural and interfacial effects that occur at the micro- and nanolevels and determine the performance characteristics of materials. The elemental composition of the filler was investigated using X-ray fluorescence analysis, which enabled the identification of mineral components capable of forming active centers that facilitate interfacial interaction with the epoxy matrix. The organic component of the filler was investigated by gas chromatography with mass spectrometric detection. At the same time, the presence of fatty acids and their glycerol esters with polar functional groups capable of participating in intermolecular interactions was revealed. It has been proven that the introduction of a filler with a content of q = 1,0…1,5 wt.% provides an increase in the destructive stresses during bending, the modulus of elasticity, the impact strength of epoxy composites, and a complex of thermophysical properties. This is due to the action of various mechanisms, in particular physical reinforcement and stress relaxation in the polymer volume. The results of comprehensive studies confirm that the biogenic lignocellulosic filler performs not only the role of a dispersed reinforcing component, but also the function of a structure-forming element that provides directed control of the properties of epoxy composites due to nanolevel interfacial interaction. This opens up prospects for creating functional polymer materials with predicted physical, mechanical and thermophysical characteristics.