Preserving the Cellular Tissue Structure of Maize Pith Though Dry Fractionation Processes: A Key Point to Use as Insulating Agro-Materials

Abstract

Plant biomass has various compositions and structures at different scales (from the component organs to their constitutive tissues) to support its functional properties. Recovering each part of the plant without damaging its structure poses a challenge to preserving its original properties for differential dedicated end uses, and considerably increases its added value. In this work, an original combination of grinding based on shearing stress and separation based on particle size and density was successfully used to sort rind (65% w/w) and pith (35% w/w) from maize stem internodes. More than 97% of the rind was isolated. The pith alveolar structure was well preserved in coarse particles, making them suitable for insulation bio-based composite materials, a promising alternative to conventional nonbiodegradable insulation panels. Boards produced from the dry fractionated pith exhibited thermal conductivities like those produced from hand dissected pith, with values equal to 0.037 W·mK−1 and 0.039 W·mK−1, respectively. In the finest fraction (particle size <1 mm), the pith vascular bundles (around 300–400 µm in diameter) were dissociated from parenchyma cells and successfully isolated using a cutting-edge electrostatic separator. Their structures, which provide the plant structural support, make them potentially valuable for reinforcement in composite materials.

Influence of the Size of the Fiber Filler of Corn Stalks in the Polylactide Matrix Composite on the Mechanical and Thermomechanical Properties

“…The density differences between the composites studied may have been influenced by the content of various components of the corn stalk including the skin and flesh. The skin has a higher density than the flesh [ 43 ].…”

“…The material was sieved in batches of 50 g for a period of 10 min at an amplitude of 2.5 Hz. A 120 g fraction obtained on each of the 2 mm, 1.6 mm, 1 mm, and 0.8 mm mesh sieves was used for further testing due to the higher mass proportion of corn stalk skin in these fractions [ 43 ].…”

“…Corn stalks can be used to produce biogas, biocarbon, and biomethane [ 39 , 40 , 41 ]. Chipboard [ 42 ], insulation boards, and polymer composites [ 43 , 44 ] can be produced from them. Corn stalk fibers, both chemically modified [ 45 ] and unmodified [ 46 , 47 ], are used in polymer composites.…”

Conservation Environments’ Effect on the Compressive Strength Behaviour of Wood–Concrete Composites

“…In this context, agro-materials, partially produced from biomass [ 9 ], are rapidly being developed and commercialized in the construction materials market [ 10 , 11 ]. Because of their ecological nature, these agro-materials make it possible to enhance the environmental balance of construction, particularly of buildings [ 12 , 13 , 14 , 15 ]. Among the agro-materials, vegetable concretes have been designed to be used in the construction industry [ 16 , 17 ] to take advantage of their thermal, acoustic, and hygroscopic qualities [ 18 , 19 ].…”