Preparation Of Fungal Mycelium /Corn Straw Porous Composite Material

With the growing demand for"green"materials and production processes,biocomposites and bio-based materials have been widely used.In these researches,mycelium-based biocomposites have received considerable attention for their excellent performance in areas such as packaging,thermal and acoustic insulation,and furniture design.Mycelium-based materials are characterized by low energy consumption,zero contamination,fully biodegradation and economic benefit which are an ideal substitute for polymer foam plastics.In this study,maize straw was used as the main material;Flammulina velutipes mycelium,Lentinus edodes mycelium and Pleurotus ostreatus mycelium were used as natural adhesives to prepare a biodegradable mycelium-based porous composite cushion material through simple biotechnology;the effects of inoculation amount,corn stalk size,culture time and material density on its performance were investigated.The properties of two different kinds of mycelium/corn straw porous composite material prepared under the same conditions were compared.The results are as follows:(1)Optimization of preparation parameters of Flammulina velutipes mycelium/corn straw porous composite material.The composite materials were inoculated by mycelium pellet.The optimal level of three main factors,such as the inoculum quantity of Flammulina velutipes mycelium,the particle size of corn straw and the incubation time were determined by single-factor experiment using compressive strength,unit volume deformation energy,rebound rate and energy absorption efficiency as the evaluation indexes.The results showed that the optimal conditions for the preparation of Flammulina velutipes mycelium/corn straw porous composite material were as follows:inoculum quantity 3.0%,particle size of corn straw 20-60mesh,incubation time 10 d.The properties of the porous composite materials prepared under the optimal formula were as follows:the compressive strength 93.02 KPa,the rebound rate 33.17%,the unit body deformation energy 8.72×10~4J/m~3,the energy absorption efficiency 0.25.(2)Optimization of preparation parameters of Lentinus edodes mycelium/corn straw porous composite material.The composite materials were inoculated by mycelium pellet.The optimal level of three main factors,such as the inoculum quantity of Lentinus edodes mycelium,the particle size of corn straw and the incubation time were determined by single-factor experiment using compressive strength,unit volume deformation energy,rebound rate and energy absorption efficiency as the evaluation indexes.The results showed that the optimal conditions for the preparation of Lentinus edodes mycelium/corn straw porous composite material were as follows:inoculum quantity 1.8%,particle size of corn straw 20-60 mesh,incubation time 15 d.The properties of the porous composite materials prepared under the optimal formula were as follows:the compressive strength 70.72 KPa,the rebound rate 30.44%,the unit body deformation energy 7.26×10~4J/m~3,the energy absorption efficiency 0.25.The performance of Lentinus edodes mycelium/corn straw porous composite material was worse than that of Flammulina velutipes mycelium/corn straw porous composite material.(3)Optimization of preparation parameters of Pleurotus ostreatus mycelium/corn straw porous composite material.The composite materials were inoculated by the solid strain.The optimal level of three main factors,such as the inoculum quantity of Pleurotus ostreatus mycelium,the particle size of corn straw and the incubation time were determined by single-factor experiment by using compressive strength,unit volume deformation energy,rebound rate and energy absorption efficiency as the evaluation indexes.The results showed that the optimal conditions for the preparation of Pleurotus ostreatus mycelium/corn straw porous composite material were as follows:inoculum quantity 20%,density of porous material16.5g/cm~3,incubation time 20 d.The properties of the porous composite materials prepared under the optimal formula were as follows:the compressive strength 56.86 KPa,the rebound rate 37.06%,the unit body deformation energy 7.25×10~4J/m~3,the energy absorption efficiency0.22.In summary,the mycelium/corn stalk porous composite materials prepared by different strains could be used as a cushion material in the field of transportation and packaging due to its excellent cushioning properties and environmental friendliness.This study provides not only a new way for the reuse of corn straw,but also an experimental reference for the development of mycelium-biofiber composites.