On the elastic modulus of hybrid particle/short-fiber/polymer composites

In this investigation, the elastic modulus of hybrid particle/short-fiber/polymer composites was studied using the rule of hybrid mixtures (RoHM) equation and the laminate analogy approach (LAA). In the RoHM, such a hybrid composite was treated as a hybrid system consisting of two separate single systems, namely particle/polymer system and short-fiber/polymer system. Thus, no interaction between particles and short-fibers could be considered. Then, the elastic modulus of the hybrid composite was evaluated from that of the two single systems using the RoHM. In the LAA, particle-filled polymer was regarded as an effective-matrix. The interaction between particles and short-fibers was incarnated in a manner that short-fibers were incorporated into the effective-matrix containing particles. The modulus of the short-fiber reinforced effective-matrix composite was then estimated using the LAA. In addition, the two approaches were applied to previous experimental results. It was interestingly observed that the predicted values by the LAA and the experimental results for the elastic modulus of hybrid particle/short-fiber/polymer composites were consistently higher than those predicted by the RoHM, suggesting that the modulus of hybrid particle/short-fiber/polymer composites shows a positive hybrid effect.