| Summary: | 碩士 === 國立臺北科技大學 === 有機高分子研究所 === 102 === The poly(tetramethylene oxide) (PTMO, M.W. = 2900) and the 4,4 ''- diphenylmethane diisocyanate (MDI) with a molar ratio of 1:3 were reacted at 70 oC in nitrogen atmosphere to form the prepolymer, and the product was subsequently chain-extended with the 1,4 - butanediol (1,4-BD) and the N-BOC-protected serinol (N-BOC-serinol) to obtain the modified polyurethane (PU). The N-BOC groups were deprotected from the synthesized PU using the trifluoroacetic acid to obtain the NH2- functionalized PU. The multi-walled carbon nanotubes (MWNTs) were calcined at 570 oC to remove the amorphous carbon, and then acidified (H2SO4/HNO3 at 3/1 vol.) at 60 oC to get the COOH-functionalized MWNTs (AMWNTs). The AMWNTs were chloroacylated (SOCl2) at 70 oC under N2 to produce the COCl-functionalized MWNTs (ClMWNTs). The NH2- functionalized PU was either chemically reacted with the ClMWNTs or physically mixed with AMWNTs to yield the composite, PU/MWNTs, or PU/ AMWNTs, respectively.
The Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectra identified the chemical structures of the PU/MWNTs and PU/ AMWNTs composites. The temperature for 95% mass remained (Td) obtained from the thermogravimetric analysis (TGA), the glass transition temperature (Tg), the melting temperature (Tm), and the crystallinity measured by the differential scanning calorimetry (DSC), the tensile strength and the Young’s modulus collected from tensile tester all increased with an increase in the amount of the MWNTs or the AMWNTs in the composite. The surface resistance of the composite decreased due to the addition of the MWNTs or the AMWNTs. A value of 3.92E +05 (Ω/cm2) reached for the composite with a 5% MWNTs loading.
The shape memory tests showed that the 4PU5 possessed the shape retention, 81.3% and the shape recovery, 97.5%.
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