Development of glutinous biocomposite materials filled with coffee grounds

Abstract

The intensive development of biocomposite materials is associated with the use of waste from agricultural production or the food industry as raw materials. Such raw materials are renewability and eco-friendly, but require special processing for preparation for use as a filler and development of methods of forming biocomposite products, which determines the high relevance of research in this direction. The aim of the work was to study the intensity of the influence of the mechanical and thermal fields on the mechanical properties and nature of the structuring of glutinous biocomposite materials with a high content of coffee grounds (190-200 wt. parts). The forming technology of biocomposite materials consisted in heat treatment of the composition. Next stages are pressing and holding of composition at a temperature of 150°C under a pressure of 8-11 MPa. The work used the methods of determining a compressive strength and an impact toughness. The method of infrared spectroscopy was also used to study structuring processes. It was established that the use of coffee grounds in the quantity of 200 wt. parts provides an increase in compressive strength up to 75.8 MPa under the condition of forming a biocomposite material with a density of 1.17 g/сm3. An increase in the resistance of biocomposites to dynamic loads occurs in the case of the introduction of a filler in the amount of 190 wt. parts using a preliminary pressing at a specific load of 8 MPa. The practical significance of this work lies in developing an optimal thermo-mechanical processing mode, involving maximum exposure of the composition in a press mould within a thermal field for 2 hours, which enhances the mechanical properties of glutinous biocomposite materials.