Biochar, an organic, porous, and carbon-rich material originating from biomass via pyrolysis, showcases compelling attributes and intrinsic performances. Its appeal as a reinforcement material for biocomposites, as well as its auspicious electrical properties, has gained more attention, and makes biochar a versatile candidate for applications ranging from energy storage to catalytic devices. This scientific review undertakes a comprehensive exploration of biochar, spanning production methodologies, physicochemical intricacies, and critical process parameters. The focus of this paper extends to optimization strategies for biochar properties tailored to specific applications, with a dedicated inquiry into diverse production methods and activation strategies. This review’s second phase delves into a meticulous analysis of key properties within biochar-based composites, emphasizing limitations and unique performance characteristics crucial for diverse applications. By synthesizing a substantial body of research, this review aims to catalyze future investigations by pinpointing areas that demand attention in upcoming experiments, ultimately emphasizing the profound potential of biochar-based materials across technical and scientific domains.

A trilayer film based on thermoplastic starch (TPS) for the core layer and poly(ε-caprolactone) (PCL) for the skin layers was obtained by coextrusion. Ascorbic acid and iron powder were added at respectively 15% and 1.5% w/w in the TPS layer for their capacity to act as oxygen scavenger, making the film usable as active food packaging. This study demonstrates that these compounds also play a role in the interactions between the different layers. FTIR measurements show that ascorbic acid migrates at the interface between TPS and PCL, where it acts as a compatibiliser between both polymers, probably by creating new interactions between polar functions of both polymers. This leads to a better adhesion of the different layers, demonstrated by the increase of the adhesion energy from 4.10⁻³ N·mm⁻¹ for the multilayer film TPS-PCL to 12.10⁻³ N·mm⁻¹ for the multilayer film containing the active components. Thanks to this compatibilising effect, the mechanical properties of the multilayer film containing ascorbic acid and iron are widely improved with an average maximal tensile strength of 7 MPa, against 3.7 MPa for the multilayer film without the active components and with an elongation at break of respectively 1450% against 290%. However, despite the hydrophobicity of PCL, the water sorption of the TPS-based layer is only slightly reduced. The multilayer film shows active oxygen scavenging properties but the rate of this reaction is divided by two compared to the active film without PCL layers (15 days to reach less than 1% oxygen for the active film without PCL layers and approximately 30 days to reach the same oxygen level with the multilayer active film).

The use of agricultural by-products in the building engineering realm has led to an increase in insulation characteristics of biobased materials and a decrease in environmental impact. The understanding of cell wall structure is possible by the study of interactions of chemical compounds, themselves determined by common techniques like Van Soest (VS). In this study, a global method is investigated to characterise the cell wall of hemp shiv. The cell wall molecules were, at first, isolated by fractionation of biomass and then analysed by physical and chemical analysis (Thermal Gravimetric Analysis, Elementary Analysis, Dynamic Sorption Vapor and Infra-Red). This global method is an experimental way to characterise plant cell wall molecules of fractions by Thermal Gravimetric Analysis following by a mathematical method to have a detailed estimation of the cell wall composition and the interactions between plant macromolecules. The analyzed hemp shiv presents proportions of 2.5 ± 0.6% of water, 4.4 ± 0.2% of pectins, 42.6 ± 1.0% (Hemicellulose–Cellulose), 18.4 ± 1.6% (Cellulose–Hemicellulose), 29.0 ± 0.8% (Lignin–Cellulose) and 2.0 ± 0.4% of linked lignin.

Renewable dielectric materials have attracted the attention of industries and stakeholders, but such materials possess limited properties. This research focused on studying polylactic acid (PLA)/cellulose acetate (CA) blends produced by 3D printing to facilitate their integration into the electrical insulation field. The dielectric findings showed that a blend containing 40% of CA by weight had a dielectric constant of 2.9 and an electrical conductivity of 1.26 × 10⁻¹¹ S·cm⁻¹ at 100 Hz and 20 °C while exhibiting better mechanical rigidity in the rubbery state than neat PLA. In addition, it was possible to increase the electrical insulating effect by reducing the infill ratio at the cost of reduced mechanical properties. The differential scanning calorimetry, broadband dielectric spectroscopy, and dynamic mechanical analysis results showed that the PLA plasticizer reduced the energy required for PLA relaxations. These preliminary results demonstrated the benefits of using a combination of PLA, CA, and 3D printing for electrical insulation applications.