Evaluation of the role of functionalized CNT in glass fiber/epoxy composite at above- and sub-zero temperatures: Emphasizing interfacial microstructures

Present work is aimed to elucidate the temperature dependant reinforcement efficiency due to the chemical restructuring of the nano-filler/matrix interphase in carbon nanotube embedded glass fiber/epoxy composite. Oxidized CNT/glass/epoxy composite exhibits 25% and 10% better strength than control glass/epoxy (GE) and pristine CNT/glass/epoxy composites respectively, at room temperature. Covalently bonded CNT/epoxy interface in oxidized nanotube modified epoxy matrix restricts the interfacial debonding to a better extent than pristine one upon excursion to elevated temperature. However, due to massive interfacial decohesion, both these nanophased GE composites result in inferior strength over control GE at 110 °C. On the contrary, mechanical gripping at the CNT/epoxy interface at lower temperature maximizes its failure strength, resulting in an admirable structural material for low and cryogenic temperature applications. Thermo-mechanical properties and microscopic evidences of the interfaces at nanoscale (CNT/epoxy) and microscale (glass/epoxy) divulge the synergetic strengthening effect due to both chemical functionalization and low temperature environment.