This paper summarizes the results obtained in the course of the development of a specific group of biocomposites with high functionality of flame retardancy, which are environmentally acceptable at the same time. Conventional biocomposites have to be altered through different modifications, to be able to respond to the stringent standards and environmental requests of the circular economy. The most commonly produced types of biocomposites are those composed of a biodegradable PLA matrix and plant bast fibres. Despite of numerous positive properties of natural fibres, flammability of plant fibres is one of the most pronounced drawbacks for their wider usage in biocomposites production. Most recent novelties regarding the flame retardancy of nanocomposites are presented, with the accent on the agents of nanosize (nanofillers), which have been chosen as they have low or non-toxic environmental impact, but still offer enhanced flame retardant (FR) properties. The importance of a nanofiller’s geometry and shape (e.g., nanodispersion of nanoclay) and increase in polymer viscosity, on flame retardancy has been stressed. Although metal oxydes are considered the most commonly used nanofillers there are numerous other possibilities presented within the paper. Combinations of clay based nanofillers with other nanosized or microsized FR agents can significantly improve the thermal stability and FR properties of nanocomposite materials. Further research is still needed on optimizing the parameters of FR compounds to meet numerous requirements, from the improvement of thermal and mechanical properties to the biodegradability of the composite products. Presented research initiatives provide genuine new opportunities for manufacturers, consumers and society as a whole to create a new class of bionanocomposite materials with added benefits of environmental improvement.

In this study, the natural dye was extracted from Spartium junceum L. (SJL) flowers and applied on cellulose (cotton) and protein (wool) fabric. Fabrics were pre-mordant with alum prior to the dyeing process. Considering the global requirements on zero waste and green policy, the dyeing process was intended to be as much as possible environmentally friendly but still effective. Therefore, mordant concentration was optimized due to the reduction of the negative impact. The efficiency of the dyeing process was investigated by examination of fabrics’ color characteristics and colorfastness to washing properties. In this paper, we have proved that the extracted dye from Spartium junceum L. is an acidic dye (mordant dye) which is more applicable for the treatment of wool fabrics. In this paper, it was proved that phytochemicals responsible for coloring are part of the flavonoids group. The UV absorption spectra of extracted dye show 4 bands in the region of λ_max 224, 268, 308 and 346 nm which are ascribed to bands characteristic for flavonoids. Wool fabric pre-mordant with 3% alum and dyed shows great chromatic (C*) properties where C* value is in a range from 47.76 for unwashed samples to 47.50 for samples after 5 washing cycles and color hue (h°) is in a range 82.13 for unwashed samples to 81.52 for samples after 5 washing cycles. The best result regarding the colorfastness properties is shown by the wool sample treated with 3% alum after 5 washing cycles (total difference in color (Delta E*) = 0.87). These results confirm that metal (Al) from alum mordant make strong chemical bonds with wool substrate and dye since Delta E* values decrease in comparison to Delta E* values of the cotton samples treated the same way. The results revealed it is possible to reduce the concentration of mordant up to 3% and obtain satisfactory results regarding the colorfastness. Nevertheless, future research will go in the direction of replacing synthetic mordant with a more environmentally friendly one.

After a long break, Spanish broom gained interest as a natural, sustainable and renewable fibre for textile and technical applications. This paper describes the characterization of Spanish broom fibres (Spartium junceum L.) in comparison to the flax fibres (Linum usitatissimum). Spanish broom fibres were obtained by two different methods of maceration and some of the most significant chemical and physical properties of tested fibres are reported. Scanning electron microscopy has proven to be a useful tool for the determination of morphological characteristics of elementary and technical fibres. Other physical-chemical properties of fibres were determined by infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), fineness and tensile strength methods.

Straw, the primary agricultural waste, constitutes approximately 20% of the total biomass in the EU. Only a small fraction of the material is applied in various products, e.g., animal bedding, mulch, building, and composite materials, while a significantly larger portion is often burned in the field. This practice, while prohibited for several reasons, including the increased risk of fire and the release of carbon dioxide contributing to global warming, is still prevalent. Given the increasingly evident effects of climate change, EU legislation aims to reduce greenhouse gas emissions as much as possible. One of the strategies includes applying the cascade principle in the circular economy. This principle aims to use the entire raw material, in this case, cereal crops, such that the products with the highest added value, like cellulose fibers from cereal straw, are extracted first. The vast potential for utilizing lignocellulosic agro-waste sustainably arises from its status as the most abundant organic compound on Earth. Its significant presence, renewability, and biodegradability make it a desirable source for producing materials in numerous industries. This study examines the potential of wheat fibers, isolated from the straw of two distinct cultivars (Srpanjka represents an old variety, and Kraljica represents the new variety) primarily for application in technical textiles. The following testing methods were applied: determination of wheat fibers and residues yield, fibers tensile properties, length, moisture content/regain, density, morphology, and Fourier transform infrared (FTIR) spectroscopy. The yield of isolated fibers relies on the wheat variety and the climatic conditions affecting plant growth, resulting in fiber yields from 10.91% to 15.34%. Fourier transform infrared (FTIR) analysis indicates reduced peak intensity, which is related to hemicellulose and lignin content, suggesting their improved deposition following the process of chemical maceration. Wheat fiber quality was found to be comparable to cotton fibers regarding its density. However, they showed a significant difference in higher moisture regain (9.72–11.40%). The vast majority of the scientific papers related to wheat fibers did not indicate the length of the individual fibers obtained by chemical maceration nor their strength. Therefore, this paper indicated that both varieties demonstrated sufficient fiber tenacity (greater than 10 cN/tex) and fiber length (2–3 cm), stressing the spinning potential of these fibers into yarns and extending their use to the apparel industry. Moreover, our research underscores the feasibility of adhering to the zero-waste principle. A high percentage of solid waste remaining after fiber extraction (25.3–39.5%) was successfully used for biofuel production, thus closing the loop in the circular economy.

The potential for sustainable lignocellulosic agro-waste is immense, owing to the fact that it represents the most abundant organic compound on Earth. It is a valuable and desirable source for material production across numerous industries due to its abundance, renewability, and biodegradability. This paper explores the world of barley fibers, which are extracted from the straw of two different cultivars (old Rex or new Barun) and have tremendous potential for use, primarily for technical textiles. The quantity of the extracted fibers depends both on the type of barley used and on climate conditions that influence the plants’ growth, resulting in fiber yields ranging from 14.82% to 19.59%. The chemical composition of isolated fibers revealed an optimal content of cellulose and lignin in barley fibers isolated from the Rex variety. Those results were confirmed with FTIR analysis, which revealed a lower intensity of peaks associated with hemicellulose and lignin and, therefore, indicated their better removal after the chemical maceration process. In terms of fiber density, the quality of the fibers was comparable to that of cotton fibers, but they differed significantly in moisture regain (10.37–11.01%), which was higher. Furthermore, sufficient fiber tenacity (20.31–23.08 cN/tex) was obtained in a case of old-variety Rex, indicating the possibility of spinning those fibers into yarns, followed by their extended usage for apparel. Additionally, our paper reveals the possibility of fulfilling the requirements of the zero waste principle due to the fact that a high percentage of solid waste left after the fiber extraction (26.3–32.3%) was afterwards successfully used for the production of biofuels, enabling the closing of the loop in a circular economy.

This research follows the principles of circular economy through the zero waste concept and cascade approach performed in two steps. Our paper focuses on the first step and explores the characteristics of developed biocomposite materials made from a biodegradable poly(lactic acid) polymer (PLA) reinforced with natural fibers isolated from the second generation of biomass (agricultural biomass and weeds). Two plants, Spartium junceum L. (SJL) and Sida hermaphrodita (SH), were applied. To enhance their mechanical, thermal, and antimicrobial properties, their modification was performed with environmentally friendly additives—linseed oil (LO), organo-modified montmorillonite nanoclay (MMT), milled cork (MC), and zinc oxide (ZnO). The results revealed that SH fibers exhibited 38.92% higher tensile strength than SJL fibers. Composites reinforced with SH fibers modified only with LO displayed a 27.33% increase in tensile strength compared to neat PLA. The addition of LO improved the thermal stability of both biocomposites by approximately 5–7 °C. Furthermore, the inclusion of MMT filler significantly reduced the flammability, lowering the heat release rate to 30.25%, and enabling the categorization of developed biocomposite in a group of flame retardants. In the second step, all waste streams generated during the fibers extraction process are repurposed into the production of solid biofuels (pellets, briquettes) or biogas (bio)methane.