Delignification and Densification as a Route to Enable the Use of Wheat Straw for Structural Materials

Abstract

Cereal straw is an abundant byproduct of crop production. Despite little current use in materials, the biologically optimized structure, which carries the weight of a structure up to 1.5 m high and protects it against environmental impacts, shows considerable potential. In order to be able to use this renewable material for structural purposes, barriers such as small dimensions and a low density have to be overcome. In the present study, lignin was partially removed from wheat straw using an alkaline solution with the aim of increasing the relative cellulose content and improving malleability. Thereafter, a homogeneous, dense, and multilayered material was produced by densification at elevated temperatures. Outstanding improvements in mechanical performance were obtained compared to the untreated raw material. For the optimum variant, tensile strength increased by a factor of three (average strength 218 MPa) and elastic modulus increased by a factor of four (average 13 GPa), which is within the range of established wood-based structural materials. We propose that mild alkaline treatment as carried out in the present study may significantly facilitate the development of high-value structural materials based on little utilized cereal straw.

Scalable, Flexible, and Highly Transmission Sweet Sorghum Film

“…Furthermore, the nondestructive inelastic collapse of the tissue structure resulted in SF being a more homogeneous material than NS and DS. Pressure and temperature played crucial roles in achieving cellular ductility through nondestructive compaction. ,, …”

“…The comprehensive utilization of agricultural waste resources offers a sustainable solution to alleviate the strain on wood resources. ,, Various agricultural residues such as wheat straw, rice straw, cotton straw, and flax shavings successfully converted into valuable derivatives like pulp, synthetic boards, compost, and porous carbon. Another promising agricultural resource is sweet sorghum, a nonfood crop with great potential to produce value-added products. − Sweet sorghum is a photosynthetically efficient crop with high biomass yield, adaptability, and tolerance to salt/alkaline conditions and drought. − The composition of sweet sorghum is similar to wood, mainly comprising cellulose, hemicellulose, and lignin, , The stems of sweet sorghum consist of internodes, which encompass pith tissue and outer bark . The outer bark possesses a denser and tougher fiber arrangement compared with the pith tissue.…”