Utilizing Fish scales as an bioadditive to enhance the thermal insulation and mechanical properties to coir-polypropylene biocomposites

This study shows that the addition of fish scales into coir-polypropylene composites provides high thermal resistance and also substantially improves mechanical properties and acoustic absorption required for civil, automotive and other applications. Fish scales (FS) are inevitably generated as byproducts and are a sustainable and renewable resource with unique structure and properties. Coir-based composites lack the performance properties particularly, flame resistance, thermal and acoustic resistance required for acoustic panelling and false ceiling applications. In this study, fish scale powder was included as an additive (5–30% by weight) and changes in the mechanical properties, flame, thermal and acoustic resistance were investigated. A substantial increase in tensile strength of up to 83% and flexural strength by 30% was possible due to the addition of fish scale powder. The FS powder blocks the pores between the matrix and reinforcement leading to higher acoustic (sound absorption coefficient of up to 0.45) and thermal insulation (0.031W/mK). Composites obtained in this study have properties better than many biobased composites of similar density and are considered suitable for automotive, civil and other applications.