Tailoring the vibration damping behaviour of flax fibre-reinforced epoxy composite laminates via polyol additions

In the present work, the addition of glycerol and polyglycerol was found to increase the damping coefficient of flax composites by 10–13% and 21–25%, respectively, according to dynamic mechanical thermal analysis and acoustic testing. The damping coefficients of the polyol-treated flax composites were larger than those of the non-treated flax and the aramid- or carbon-fibre composites prepared under similar conditions. The relatively high damping behaviour of polyol-treated flax fibre reinforced composite is attributed to a stick–slip mechanism that involves the cyclic breaking and reformation of hydrogen bonds between the polyols and lamellae of the cell walls or microfibrils within the lamellae.