Enhanced damping and stiffness trade-off of composite laminates interleaved with recycled carbon fiber and short virgin aramid fiber non-woven mats

This paper proposes composite laminates interleaved with recycled carbon fiber and short virgin aramid fiber non-woven mats to enhance the trade-off of mechanical damping and stiffness. Compared with their virgin counterparts, recovered carbon fibers (rCFs) have the potential for damping enhancement at the cost of only minimal degradation in strength. A papermaking method was used to convert rCFs and virgin aramid fibers (vAFs) separately into 60 g/m² non-woven mats, which were then sandwiched between two layers of 125 g/m² epoxy resin films before interleaving. A vacuum-assisted compression molding process was then used to produce the laminates. The effect of a titanate coupling agent on the adhesion between the mats and the epoxy matrix was studied. The experimental results showed that the titanate coupling agent was an effective sizing agent for rCF and vAF mats with epoxy matrix. The laminate with a single core layer of sized rCF mat showed better flexural properties and dynamic performance than those with the sized vAF mat. The flexural modulus and dynamic properties were found to depend on the stacking sequence of the added non-woven mats. Compared with the control sample, the best laminate had a figure of merit of 0.73 GPa, which was 23.7% higher.