In-Situ X-ray Deformation Study of Fluorinated Mulitwalled Carbon Nanotube and Fluorinated Ethylene-Propylene Nanocomposite Fibers

Journal Article · Sun Jan 01 04:00:00 EST 2006 · Macromolecules

DOI:https://doi.org/10.1021/ma060173u· OSTI ID:914323

Chen, X; Burger, C; Fang, D; Sics, I; Wang, X; He, W; Somani, R; Yoon, K; Hsiao, B; Chu, B

A fluorinated multiwalled carbon nanotube (FMWNT) was prepared by reaction of 3-perfluorooctylpropylamine with carboxylic acid groups on the oxidized carbon nanotube surface. The modification was confirmed by TGA, TEM, and solubility tests in a perfluorodecalin solvent. Nanocomposite fibers based on FMWNT and a fluoro-ethylene-propylene (FEP) copolymer were fabricated by melt blending and melt spinning. SEM examination indicated that the dispersion of FMWNT in FEP was significantly better than that of the as-received multiwalled carbon nanotube (MWNT) in FEP. Both yield strength and modulus of the melt-spun FMWNT/FEP nanocomposite fiber increased with increasing FMWNT content, but the elongation-to-break ratio decreased. In-situ small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) techniques were used to follow the structural changes during tensile deformation of melt-spun fibers. In pure FEP fibers, perpendicularly arranged lamellar stacks (with respect to the fiber axis) became tilted at small strains, while destruction of lamellae took place at high strains (>250%), resulting in the rapid decrease of crystallinity. Surprisingly, the tilting of lamellar stacks was not observed in FEP/FMWNT nanocomposite fibers during deformation. We hypothesize that the well-dispersed FMWNT particles form a fibrous network, which can carry a significant fraction of local stress, resulting in overall increases of yield strength and modulus. A possible mechanism to explain the effect of FMWNT on the lamellar structural change in FEP and corresponding mechanical behavior is presented.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 914323
• Report Number(s): BNL--78891-2007-JA
• Journal Information: Macromolecules, Journal Name: Macromolecules Vol. 39
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARBON
CARBOXYLIC ACIDS
COPOLYMERS
DEFORMATION
FIBERS
LAMELLAE
MODIFICATIONS
NANOTUBES
SCATTERING
SOLUBILITY
STRAINS
X-RAY DIFFRACTION
YIELD STRENGTH
national synchrotron light source