The high density and poor thermal insulation of traditional wood-plastic composites limited the application in the field of building materials. In this paper, wood fiber (WF) and PLA were used as raw materials and azodicarbonamide was used as the foaming agent. Lightweight WF/PLA composites were prepared by the hot-pressing foaming method, aiming to obtain renewable, low-density material with high strength-to-weight ratio and thermal insulation performance. The results showed that after adding 20 % WF into PLA, the cell morphology was excellent and the cell size was uniform. The magnification reached the minimum value of 0.36 g/cm³ and the foaming magnification was 3.42 times. The impact strength and compressive strength were 3.16 kJ/m³ and 4.12 MPa, its comprehensive mechanical properties were outstanding. The thermal conductivity of foamed materials was 0.110–0.148 (W/m·K), which was significantly lower than that of unfoamed materials and common wood. Its excellent mechanical properties and thermal insulation can be suitable for application in the construction field to replace traditional wood.

Wood waste from construction sites represents an environmental and financial burden. Furthermore, there is a need in everyday practice to replace CO₂-intensive construction materials and especially Portland cement, with less polluting alternatives such as slag, metakaolin, hydraulic and non-hydraulic lime, or magnesium cement, among many others. In this scenario, an eco-friendly insulator made of recycled wood chips embedded in a lime-metakaolin binder was proposed and assessed for application in the construction industry. The influence of curing regimes on carbonation, microstructure, compressive and flexural strength, density, and thermal conductivity was studied. Specimens were cured in three subsequent environments of variable duration: (i) under a plastic sheet with high moisture content, (ii) exposed to drying in standard lab conditions and, (iii) in a CO₂ incubator. Pre-conditioning of the specimens before the CO₂ curing, affected the carbonation efficiency and subsequently microstructure and mechanical properties of the biocomposite. Carbonation rate (from different curing regimes) affected mechanical properties also when comparing fully carbonated specimens, leading to different engineering properties of the biocomposite. Density and thermal conductivity were less impacted overall.

The continually expanding use of plastic throughout our world, along with the considerable increase in agricultural productivity, has resulted in a worrying increase in global waste and related environmental problems. The reuse and replacement of plastic with biomaterials, as well as the recycling of agricultural waste, are key components of a strategy to reduce plastic waste. Agricultural waste is characterized as lignocellulosic materials that mainly consist of cellulose, hemicellulose, and lignin. Saprobe fungi are able to convert agricultural waste into nutrients for their own growth and to facilitate the creation of mycelium-based composites (MBC) through bio-fabrication processes. Remarkably, different fungal species, substrates, and pressing and drying methods have resulted in varying chemical, mechanical, physical, and biological properties of the resulting composites that ultimately vary the functional aspects of the finished MBC. Over the last two decades, several innovative designs have produced a variety of MBC that can be applied across a range of industrial uses including in packaging and in the manufacturing of household items, furniture, and building materials that can replace foams, plastics, and wood products. Materials developed from MBC can be considered highly functional materials that offer renewable and biodegradable benefits as promising alternatives. Therefore, a better understanding of the beneficial properties of MBC is crucial for their potential applications in a variety of fields. Here, we have conducted a brief review of the current findings of relevant studies through an overview of recently published literature on MBC production and the physical, mechanical, chemical, and biological properties of these composites for use in innovative architecture, construction, and product designs. The advantages and disadvantages of various applications of mycelium-based materials (MBM) in various fields have been summarized. Finally, patent trends involving the use of MBM as a new and sustainable biomaterial have also been reviewed. The resulting knowledge can be used by researchers to develop and apply MBC in the form of eco-friendly materials in the future.

The first part of this report deals with peat as a natural resource in the three Scandinavian countries; Denmark, Norway and Sweden. Mires with peat receive raised awareness today with increased climate change and decreased biodiversity. The authorities and several non-governmental organizations are advocating to reduce the use of peat. Communication is often directed towards private users, who undertake about half of the peat sold for growing media as estimated both by volume and value. Private growers may act as a driver for change to reduce peat use because they can afford to pay more for alternatives than commercial growers, and they can take more risks if growing media do not always perform well. Organic regulations restrict the use of peat to horticulture. Since mineral nitrogen fertilisers may not be applied in organic growing, the development of growing media for the organic sector may increase our knowledge on applicability of organic materials more rich in nutrients than peat e.g. composts. Scandinavian studies on peat-reduced growing media are plenty but the results are not always translated to or explained in English. Research and industry have cooperated in the attempts to replace peat. Students have done efforts to find solutions and several written works are published. Wood products, possibly composted, are relevant to replace peat in growing media in Scandinavia where woody material is plenty. Other materials to be applied could be solid digestate from biogas plants, waste from industry and agriculture or residual materials from private gardens and public green areas. Substrates applied in growing media need to be studied both separately and in mixtures. Volume, processing and price are other factors to be considered. Because peat has unique properties as growing media, cultivation of white mosses in “paludi-culture” has received some interest and is briefly described in the report. The report briefly presents some peat-free products available on the Scandinavian market in 2021. The markets overlap country boarders and change rapidly from year to year. The report is written with funding from the Horizon 2020 project “Pathways to phase-out contentious inputs from organic agriculture in Europe” (Organic-PLUS), GA774340 (2018-2022), where NORSØK leads a work package on fertilisation, growing media and degradable plastic in organic farming. The purpose of the report is to present in the English an overview of studies conducted in Scandinavia to phase out peat from growing media.