Methodology for assessing the degree of biodegradability of plastics based on lignocellulose-containing raw materials without resins

Abstract

Currently, technologies have been developed and implemented to transform the biomass from lignocellulosic-containing raw materials (including wood), without the addition of synthetic binders, into composite materials with various applications. For these materials, the common term resinless "plastic", or abbreviated PWR, has become somewhat popular. The current test methods for determining the extent of biodegradation are not suitable for PWR. This facilitates determining the degree of biodegradability of PWR based on various pressing materials. A scoring-rating system was developed to assess the degree of biodegradability of PWR based on lignocellulosic raw materials, using the identified 5 main criteria when aged 85 days in the soil. The proposed scoring system was tested on samples of PWR derived from various pressing materials, including pine, birch, and larch sawdust, vegetative residues of knotweed and industrial hemp, wheat bran, and deciduous litter. The test results of PWR were processed using the proposed evaluation methodology, helping determine the potential for biodegradation of the investigated materials. In general, PWR-based materials can be characterized as materials with a high potential for biodegradation. The most potential for biodegradation can be considered PWR based on pine and leaf litter, which degrade as much as possible in the soil in 85 days. The established individual degrees of biodegradability of PWR based on various lignocellulosic raw materials were interpreted in the context of previously obtained results regarding the properties of the original raw materials. Thus, a conclusion was drawn that the degree of biodegradability of PWR is influenced by the properties of the original plant raw material under identical piezothermal treatment conditions during material production.