Investigating the role of filler shape on the dynamic mechanical properties of glass‐filled epoxy composites

Abstract

AbstractThe influence of filler shape and volume fraction on the dynamic mechanical characteristics of rigid glass filler epoxy composites is investigated. Two variants of glass fillers, spherical particle and slender (milled) fibers, are doped into the epoxy matrix till 10% volume fraction. The composites are room temperature cured and tested to measure their viscoelastic properties. The dynamic mechanical analyses performed in the temperature range of 20–180°C at 10 Hz suggest that the milled fiber composites display consistently higher storage and loss moduli, whereas the higher loss factor peaks were noted for the spherical particle composites. The C‐factor, filler reinforcement efficiency of the composites and entanglement density, evaluated from the storage modulus values, indicate that the milled fibers composites are more effective in transferring the loads in both glassy and rubbery zones when compared against the spherical particle case. Also, the filler/matrix adhesion factor (A factor) and the interphase adhesion factor, calculated from the loss factor curves reveal stronger filler/matrix interactions in the case of milled fiber epoxy composites. Interestingly, the filler geometry or volume fraction has only marginal influence on the glass transition temperature of the composites.