Physical and mechanical properties of boards made from modified rapeseed straw particles

Abstract

Composites made from annual plants, such as winter rapeseed, can be used as an alternative to wood-based composites because of their ecological character, low price, as well as physical and mechanical properties. The goal of this study was to prepare such boards and evaluate their properties. Unmodified material and chemically and hydrothermally modified rapeseed particles glued by powder polyester glue were used. The characteristics measured were the internal bonding, swelling and moisture uptake over time, and surface soundness. The results showed that modification of the raw material influenced the properties of the resulting composites. The highest swelling values were exhibited by the boards with particles that were alkaline-modified. Boards made from hydrothermally modified particles achieved the highest strengths compared with the commercially produced boards. The alkaline modification of the particles resulted in a stronger adhesive bond between the particle and adhesive. During the internal bonding test, the boards made from the alkaline-modified particles exhibited cohesive failures in the particles. Therefore, the modification of the particles increased the mechanical properties of the boards, but the physical properties deteriorated.

Analysis of the properties of alkaline-treated rape straw and stalk polyvinyl chloride composites

“…52 Moreover, in section of Figure 7(c) SWC indicates a strong bond resulted in fiber damage that could be attributed to the high alkaline concentration throughout the damage process, although the fibermatrix interface was greatly similar to the SKC counterpart (Figure 7(f)) of the same 7% alkalinetreated. [53][54][55] The interfacial improvement observed in Figure 7(b) and 7(e) which are 1% alkaline-treated in both SWC and SKC confirms the result obtained in mechanical properties, and implies that stress can be effectively transferred to the fiber from the matrix with moderate alkaline concentration treatment. Further increases in alkaline concentration can result in poor mechanical properties.…”

Effect of cold plasma surface pre-treatment of wheat straw particles on straw board properties

“…There was no statistically significant difference between the different plasma treatments. Both observed mechanical properties reached lower values than the boards made form rapeseed stalk particles, where internal bonding was 0.34 MPa to 0.50 MPa and the bending strength was 5 MPa to 10 MPa (Hýsek et al 2018). However, in previous research, boards with an average density of 600 kg/m 3 and with an inverse vertical density profile (maximal density in the middle of the board) were produced.…”

“…This was explained by the material used. From the authors' previous study it is already known that boards produced from after harvest remains reached non-recoverable thickness changes higher than 30% (Hýsek et al 2018). It was concluded that the plasma treatment of the particles had a statistically significant effect on the equilibrium moisture content of the boards and their thickness swelling; however, the thickness swelling values were negatively affected by the different average densities of the boards.…”

Characterization of Self-Growing Biomaterials Made of Fungal Mycelium and Various Lignocellulose-Containing Ingredients

“…The volumetric swelling of MB specimens was lower than reported for other composite materials. The swelling of rapeseed particles reached ~35%, but for particleboards and OSB ~20% [ 37 ]. A low volumetric swelling versus high water absorption can be explained by the porous structure of MB materials that were filled with high amounts of liquid with no further swelling capacity.…”