Biocomposite materials manufactured from natural fibres and polymer matrix represent a group of engineered composite products with diverse applications. These materials continue to find increasing applications due to their design flexibility, superior properties and aesthetic appeal. The applicability of these biocomposites, however, depends on the interaction in the fibre-matrix interface. This paper reviews the state of the art research in fibre-matrix interfacial interaction based on published literature. A brief background on biocomposite materials is presented. The focus of this review is the modification of natural fibres and its effect on fibre-matrix interfacial adhesion and properties. In addition, the effect of chemical treatment on fibre composition and fibre-matrix interfacial bonding mechanism are discussed.

In recent years, there has been a growing interest in many parts of the world for more effective biomass utilization due to legislative and public interest in sustainable development. Whilst much of the effort has been on energy generation from biomass, there is considerable interest on biomass availability and utilization for other end uses. With about 1% of the world’s commercial forest areas, Sweden provides about 10% of the sawnwood, and pulp and paper that is traded on the global market. The Swedish agricultural sector also contributes to biomass availability, not only by production of sustainable food crops, but also by utilizing side streams and underutilized land for biomaterial purposes. To meet the challenges that climate change presents, there has to be a shift to sustainable biomass production and increased interest in promoting a circular bioeconomy. This review presents a systematic assessment on the availability of biomass and its utilization potential in Sweden. The review also focuses on biomass production and trade in the Swedish forest industry. In addition, the environmental impact of biomass utilization is discussed. Graphic

The incorporation of recycled papers, paperboards and Tetra Pak as filling materials in brittle matrices presents an interesting approach in the utilization of waste materials for building construction. This paper examines the compressive strength and microstructure of gypsum-bonded wastepaper-based composites. Recycled wastepaper of various types (office paper, magazine paper and newspaper), cardboards, paper boxes and Tetra Pak were shredded to short length strips of about 4 × 18 mm. The shredded materials were used as filling materials in natural gypsum in a ratio of 1:3 (v/v), and water was added to the mix. The paste was formed in cylindrical samples measuring 10 cm in length and 5 cm in diameter. Seven different types of composites were produced depending on the material used. The composite products with newspaper and magazine paper had significantly lower density and compressive strength (p < 0.05) than the others. However, the differences were small to have any practical importance. The density values ranged between 1.26 and 1.34 g/cm3, and compressive strength was the lowest (4.48 N/mm2) in the gypsum–magazine paper composites and the highest (6.46 N/mm2) in the gypsum–Tetra Pak I composites. Since the samples produced in this study exhibited adequate compressive strength, the products could be suitable for such applications as interior walls in building constructions. Scanning electron microscopy (SEM) examination of the fractured surfaces revealed needle-like structures of gypsite crystals surrounding the fibers, which indicates good adhesion between the hydrophobic matrix and lignocellulosic fibers.