Performance of mycelium composites of Lentinus crinitus under two compression protocols

Abstract

Considering the current environmental problems that has been generated by the excessive production of synthetic plastics, more sustainable alternatives have been proposed. One of these recently studied materials are the mycelium composites, a product obtained with lignocellulosic particles agglomerated together by the myceliar growth of a filamentous fungus. This novel type of materials could represent an option to replace non-biodegradable materials. In this work, mycelium composites with characteristics comparable to expanded polystyrene (EPS) and potentially suitable for fabrication of insulation panels were developed using a Lentinus crinitus strain previously selected after mycelial phases tests. Mechanical variables in bending, compression strength and stiffness were measured following ASTM D143 standard. Two protocols for composite fabrication were followed using different compression loads. Flexural strength reached 0.48 MPa and compression strength 0.235 MPa. Results obtained were compared with data of balsa wood (Ochroma pyramidale) for the similarity of possible applications, expanded polystyrene as its possible substitute and early published data on mycelium composites. Mechanical performance in flexural and compressive strength of the obtained materials revealed their potential use as biodegradable alternatives to some applications of synthetic plastics as insulation panels and packing materials.

Effect of Composition Strategies on Mycelium-Based Composites Flexural Behaviour

“…In the latter figure we can notice the increased mechanical efficiency of the BM_R series thanks to the composition strategy. In both figures flexural reports from the published MBC state-of-the-art are plotted [ 3 , 4 , 5 , 11 , 12 , 18 , 19 , 20 , 21 , 22 ]. These two figures gather evidences produced with approximately ten fungal species, two studies having not disclosed the ones they used [ 5 , 20 ].…”

“…Densified specimens have been reportedly leading to an increase of flexural modulus between 27 and 72-fold, and 4 to 14.5-fold increase in flexural strength for a densification from 100–130 kg/m 3 to 350–390 kg/m 3 [ 3 ]. While staying at the lower end of MBC densities, another study reported an increase of 4.4-fold in flexural strength while increasing composite density by a factor 1.4 (from 102 to 141 kg/m 3 ) [ 4 ]. Composition is a second strategy for modifying MBC behaviour by adding structural components to the substrate, including, for instance, orientated fibres or textiles.…”

Compressive behaviour of anisotropic mycelium-based composites

“…9 ). In both figures compressive characterisation from the published MBC state-of-the-art are plotted 4 – 7 , 35 – 43 . These figures gather evidences produced with approximately ten fungal species, two studies having not disclosed the ones they used 6 , 36 .…”