Mechanical and vibration damping properties of multifunctional composites incorporating elastomeric particulates

This paper investigates the effect of nonporous elastomeric fillers on both the compression and functional properties of an epoxy syntactic foam. Micro-sized elastomeric particulates (up to 23%wt.) derived from recycled waste tyres were integrated into the syntactic foam (epoxy modified by 5%wt. of hollow glass microspheres) and transformed into foam composites via injection moulding. The syntactic foam composites were evaluated under compression loading. The compression strength and compression modulus of the syntactic foam composite decreased with the addition of elastomeric fillers. At 23% wt. loading, the compression strength and compression modulus decreased by about 40%. The reduction in the compression properties was attributed to the presence of elastomeric particles which disrupted the cross-linking of the epoxy. The vibration responses (natural frequencies and damping ratio) were measured via laser doppler vibrometry (LDV). The damping ratio increased with the increase in the weight fraction of elastomeric fillers. The improvement in the vibration damping ratio was attributed to the viscoelastic nature of the elastomeric fillers.