Material development and fabrication of porous-cored nanocomposite feather

Abstract

Natural feather shuttlecocks are required by Badminton World Federation to be used in tournament competitions. The shuttlecocks are produced from goose feathers, and each goose can supply only feathers for, at most, two shuttlecocks. The supply for natural feathers is limited, and the objective of this project is to develop material substitute for feathers. Natural feathers are made from exceptional materials which are exceptionally strong for their weight. In this study, we developed methods to fabricate advanced Multi-Walled Carbon Nanotubes (MWCNTs) reinforced polyimide nanocomposites and porous polyimide as strong and lightweight material substitutes for natural feathers in shuttlecocks. MWCNTs are generally poorly dispersed in reinforced nanocomposites which would deteriorate the mechanical properties of nanocomposites. To improve dispersion and interfacial adhesion, a method to surface-functionalize MWCNTs using silane coupling agents is proposed. The dispersion stability of MWCNTs in different organic solvents is studied. The effects of functionalized MWCNTs on the properties of MWCNTs/polyimide nanocomposites are also investigated. The results show that the surface-functionalized MWCNTs attained improved dispersion within the nanocomposite matrix and interfacial adhesion with the nanocomposites matrix, resulting in 48% improvement in Young’s modulus and 52% improvement in tensile strength when compared to neat polyimide. In order to reduce the weight of polyimide, pores are induced into polyimide by vapour induced phase separation. Porous polyimide films with porosity as high as 70% and controllable pore sizes (2.3-0.5μm) are prepared. Results show that the pore structure of the porous polyimide is affected by the concentration of the polymer, the thickness of the film, as well as the processing conditions. Mechanical testing shows that the maximum strain at break of porous polyimide was 228% of dense polyimide and the specific Young’s modulus of porous polyimide improved 35% when the pore size reduced 57%. By utilizing the newly developed materials, feathers with a dense outer skin and with a porous core are designed and fabricated as an alternative to natural feathers. Experimental results show that the porous-cored nanocomposite feathers are only 13% heavier but the stiffness is 116% higher and the strain before structural failure is 142% higher than natural feathers, and that this would probably lead to a more stable and predictable flight path of a shuttlecock and a prolonged service life.

Date of Award	2012
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology