TY - JOUR
T1 - Flow induced orientated morphology and properties of nanocomposites of polypropylene/vapor grown carbon fibers
AU - Larin, Boris
AU - Lyashenko, Tatiana
AU - Harel, Hannah
AU - Marom, Gad
PY - 2011/1/17
Y1 - 2011/1/17
N2 - Nanocomposite filaments composed of isotactic polypropylene (iPP) and vapor grown carbon fibers (VGCF) were prepared by melt mixing extrusion, followed by melt drawing. The effect of composition and flow on the morphology was investigated by X-ray diffraction and high resolution scanning electron microscopy. Apparently in the drawn filaments, the presence of nanofibers resulted in a higher degree of orientated morphology and - as revealed by differential scanning calorimetry - higher degrees of crystallinity and crystallization kinetics enhancement. The amount of the orientated crystals increased as a result of VGCF addition, suggesting that the nanofibers obstructed the motion of polymer chains after the cessation of stretching force resulting in the delayed relaxation of stretched polymer segments. Significant stiffness improvements were observed due to the nanofibers and high draw ratios of the filaments. These results indicate that the orientated VGCF aligned in the flow direction, joined by fiber-induced crystallization of the surrounding iPP matrix, generate a strong stiffening effect.
AB - Nanocomposite filaments composed of isotactic polypropylene (iPP) and vapor grown carbon fibers (VGCF) were prepared by melt mixing extrusion, followed by melt drawing. The effect of composition and flow on the morphology was investigated by X-ray diffraction and high resolution scanning electron microscopy. Apparently in the drawn filaments, the presence of nanofibers resulted in a higher degree of orientated morphology and - as revealed by differential scanning calorimetry - higher degrees of crystallinity and crystallization kinetics enhancement. The amount of the orientated crystals increased as a result of VGCF addition, suggesting that the nanofibers obstructed the motion of polymer chains after the cessation of stretching force resulting in the delayed relaxation of stretched polymer segments. Significant stiffness improvements were observed due to the nanofibers and high draw ratios of the filaments. These results indicate that the orientated VGCF aligned in the flow direction, joined by fiber-induced crystallization of the surrounding iPP matrix, generate a strong stiffening effect.
KW - A. Carbon nanotubes
KW - A. Nanocomposites
KW - B. Mechanical properties
KW - E. Extrusion
KW - Orientated crystallization
UR - http://www.scopus.com/inward/record.url?scp=78650888228&partnerID=8YFLogxK
U2 - 10.1016/j.compscitech.2010.11.002
DO - 10.1016/j.compscitech.2010.11.002
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AN - SCOPUS:78650888228
SN - 0266-3538
VL - 71
SP - 177
EP - 182
JO - Composites Science and Technology
JF - Composites Science and Technology
IS - 2
ER -