Modification of buckwheat husk powder and creation of composite material on its basis

Abstract Waste of plant origin is becoming increasingly relevant for use as fillers in polymer matrices to create new composite materials. In this study, a composite material based on biodegradable thermoplastic polylactide (PLA) and buckwheat husks (BHS) was prepared. L-PLA IngeoTM Biopolymer 4043D in pellet form (Nature Works LLC, USA) was chosen as the base for the polymer matrix. BHS in the form of fine powder (harvested in 2023) was used as a plant filler. In order to purify the raw material from dust and pathogenic bacteria, as well as to increase the adhesion ability of the material, BHS was treated with 4% alkaline solution (NaOH). Modification of the filler was carried out using organosilicon resin K-9 (manufacturer Khimprodukt LLC, Lyubertsy, Russia). The filler was added to the material in the ratio of 22%, 32%, 42% by weight of the product. A technology for modification of BHS powder is proposed, which makes it possible to significantly increase the wetting angle from 59.47 ± 1.59° to 95.6 ± 1.35°. The strength properties and water absorption resistance of the developed composites with different weight ratios of PLA/ BHS are investigated. The modification of the filler changes the structure and properties of BHS, as well as contributes to the improvement of strength properties. At the ratio PLA 68 wt% / modified BHS 32 wt% the composite material has the following characteristics: density - 1342 kg m −3 , bending strength—21.31 MPa, maximum deformation value—0.22 mm, Vickers hardness at a load of 200 g—20.21, water absorption—1.9%. Research on the utilization of plant components will make it possible to integrate into industry innovative products based on renewable and biodegradable resources that will meet all societal needs and contribute to the preservation of the environment and exhaustible resources.