THESIS
2012
1 v. (various pagings) : ill. ; 30 cm
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
dete...[
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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.
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