Property enhancement of polymer-based composites at cryogenic environment by using tailored carbon nanotubes

At high attitude, all polymer-based materials would suffer from degradation at very low temperature in the range between 220 and 77 K (commonly called "at cryogenic environment") and low atmospheric pressure. Within this temperature range, polymer-based composites behave very brittle and many micro-cracks are formed due to differential thermal coefficients of expansion (CTEs) between polymer matrix and high strength reinforcements. An anti-cracking mechanism in the composites is necessary and can be tailored by using nano-particles. Many studies have addressed that the use of single-walled (SWNTs) and multi-walled carbon (MWNTs) nanotubes could enhance the mechanical properties of polymer-based composites. However, interfacial bonding properties are always an issue as it would affect the efficiency and effectiveness of stress transfer in the composites. This paper addresses the viability of using coiled carbon nanotubes (CCNTs) and randomly-oriented nanoclay-supported nanotubes (NSCNTs) to enhance the mechanical properties of epoxy resin at the cryogenic environment.