Transition to biocomposites in conditions of city urbanization

\nWith the rapid urbanization of cities, there is an increase in urban tree pruning waste, which increases the cost of their disposal. The trend of a circular economy and environmental friendliness of the urban environment dictates the need to find more effective ways to use them. The article examines the possibility of using crushed waste from fast-growing urban trees, in particular poplar, as a filler for the production of biocomposites based on polyhydroxybutyrate (PHB). To improve the performance properties of poplar wood flour, a technology for its thermal modification has been proposed, which makes it possible to neutralize such disadvantages as low strength and high hydrophilicity, characteristic of fast-growing wood. The physicomechanical and sorption properties of three types of biocomposite samples made with natural pine flour, natural and thermally modified poplar flour were analyzed. Pine wood has been chosen as a filler often used in industry for wood-polymer composite materials. It has been established that thermal modification of poplar flour provides an increase in the tensile strength of biocomposite samples by 19 %, in bending by 7.9 % and reduces water absorption by 50 % relative to samples with untreated wood. In many cases, the use of thermally treated poplar flour is comparable to the quality of a biocomposite based on pine flour. This indicates the feasibility of recycling urban tree trimming waste for the industrial production of biocomposites, which will improve the environmental friendliness of the urban environment with the simultaneous development of a green industry.\n