Viscoelastic properties of carbon nanofiber reinforced multiscale syntactic foam

The viscoelastic properties of carbon nanofiber (CNF) reinforced multiscale composites are examined in this study in the temperature range -75 to 200 degrees C. The study is focused on determining the effect of CNF and glass hollow particle content on the properties of syntactic foams. Ten different compositions of CNF reinforced syntactic foam and four different compositions of CNF/epoxy composites are evaluated for storage modulus, loss modulus, and damping parameter using a dynamic mechanical analyzer. In addition, the maximum use and glass transition temperatures are also determined. With respect to neat epoxy, the storage modulus and loss modulus for CNF/epoxy composites increase with CNF content by as much as 14.6% and 22.6% at room temperature, respectively. The loss modulus of CNF/syntactic foams is shown to increase by up to 25.3% at room temperature, and the maximum use and glass transition temperatures of CNF/epoxy composites increased by a maximum of 9.1% and 8.6%, respectively. The maximum use and glass transition temperatures of CNF/syntactic foams are observed to increase by up to 27.1% and 25.0%, respectively, with respect to neat epoxy. The ability to tailor the properties by means of CNFs and glass hollow particles and improved stabilities of reinforced syntactic foams at high temperatures is important for aerospace applications of syntactic foams. (C) 2013 Elsevier Ltd. All rights reserved.