Plastic Composites Made from Glycerol, Citric Acid, and Forest Components

An ecofriendly approach for the synthesis of plastic biomaterials based on renewable materials suitable for 3D printing application or other applications has been developed. The material was prepared from native (microcrystalline) or amorphous cellulose, citric acid, and glycerol or ethylene glycol, by a pretreatment at 40 degrees C and a curing at 175 degrees C for 1 h. The results showed that tensile properties and the water absorption level of the material were acceptable. The highest strain at break (14%) was obtained from materials made of 10% amorphous cellulose with 90% glycerol/citric acid. It had a maximum stress at 37 MPa. Moreover, materials were without ash content. Possible applications of the material in 3D-printers were discussed. In addition, application of mechanical pulp and wood powder into novel plastic material production was discussed. Foaming during curing might be a problem for this type of material, but this can be avoided by using amorphous cellulose in the recipe

Densification of Wood—Influence on Mechanical and Chemical Properties when 11 Naturally Occurring Substances in Wood Are Mixed with Beech and Pine

The need to increase the use of renewable biomasses for energy supply, such as fuel pellets is significant. However, different types of biomasses have different mechanical properties to be pelletized, which entails a limitation in available raw materials for pellet producers. Within this study eleven different pure substances from biomasses were separately mixed with European beech and Scots pine, to identify its impact on the densification process. Beech and pine pellets were used as control materials against their corresponding pellets mixed with substances representing: cellulose, hemicelluloses, other polysaccharides, lignin, protein, and extractives. The mechanical properties were investigated as well as FT-IR and SEM analyses on the pellets. The results showed that the addition of the substances xylan and galactan created the hardest pellets for both pine and beech and that adding extractives to wood affects pine more than beech in relation to hardness. The FT-IR data could not provide clear explanations as to the variation in hardness and springback behavior through the identification of major functional groups in each pellet. It can be concluded that biomass residues rich in xylan and galactan increase pellet quality in terms of strength and durability without affecting the production process