TY - JOUR
T1 - Electrospun isotactic polystyrene nanofibers as a novel β-nucleating agent for isotactic polypropylene
AU - Wang, Chi
AU - Chu, You Ling
AU - Wu, Yi Jiun
N1 - Funding Information:
This work was financially supported by National Science Council of Taiwan ( NSC 98-2221-E-006-005-MY3 ), and National Synchrotron Radiation Research Center (NSRRC, 2009-2-047-5 ). The assistance of 2-D SAXS, and 2-D WAXD experiments from Drs. U-Ser Jeng and Jey-Jau Lee in NSRRC is highly appreciated.
PY - 2012/10/26
Y1 - 2012/10/26
N2 - Electrospinning of isotactic polystyrene (iPS) solutions at 73 °C or at room temperature was feasibly carried out using ortho-dichlorobenzene as the solvent. Depending upon the solution concentration, solution temperature, and collector design, bead-free iPS fibers with diameter of 230-430 nm were successfully obtained. As-spun nanofibers were found to be amorphous and contained oriented iPS chains. The structural evolution of the amorphous iPS nanofibers during stepwise annealing was investigated through two-dimensional small-angle X-ray scattering/wide-angle X-ray diffraction measurements using synchrotron radiation sources. Both the crystal structure (i.e., crystallinity degree and crystal orientation) and lamellar morphology (i.e., lamellar thickness and long period) in the fibers were studied to reveal the possible confinement effect on crystal development. When embedded in the isotactic polypropylene (iPP) matrix, crystalline iPS fibers act as effective nucleating agents that induce iPP transcrystallization on the surface of the fiber. A thin transcrystalline (TCL) layer of α-form iPP crystals is first developed. Subsequent formation of β-form nuclei sporadically takes place at the growing front of α-form TCL, and its growth eventually becomes dominant due to its higher growth rate than the α crystal in the temperature range studied. Having a high surface-to-volume ratio and the ability to induce β-form iPP, electrospun iPS nanofibers act as a promising filler, not only in increasing crystallization kinetics but also in potentially enhancing the toughness of as-prepared nanocomposites.
AB - Electrospinning of isotactic polystyrene (iPS) solutions at 73 °C or at room temperature was feasibly carried out using ortho-dichlorobenzene as the solvent. Depending upon the solution concentration, solution temperature, and collector design, bead-free iPS fibers with diameter of 230-430 nm were successfully obtained. As-spun nanofibers were found to be amorphous and contained oriented iPS chains. The structural evolution of the amorphous iPS nanofibers during stepwise annealing was investigated through two-dimensional small-angle X-ray scattering/wide-angle X-ray diffraction measurements using synchrotron radiation sources. Both the crystal structure (i.e., crystallinity degree and crystal orientation) and lamellar morphology (i.e., lamellar thickness and long period) in the fibers were studied to reveal the possible confinement effect on crystal development. When embedded in the isotactic polypropylene (iPP) matrix, crystalline iPS fibers act as effective nucleating agents that induce iPP transcrystallization on the surface of the fiber. A thin transcrystalline (TCL) layer of α-form iPP crystals is first developed. Subsequent formation of β-form nuclei sporadically takes place at the growing front of α-form TCL, and its growth eventually becomes dominant due to its higher growth rate than the α crystal in the temperature range studied. Having a high surface-to-volume ratio and the ability to induce β-form iPP, electrospun iPS nanofibers act as a promising filler, not only in increasing crystallization kinetics but also in potentially enhancing the toughness of as-prepared nanocomposites.
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U2 - 10.1016/j.polymer.2012.09.036
DO - 10.1016/j.polymer.2012.09.036
M3 - Article
AN - SCOPUS:84867672028
SN - 0032-3861
VL - 53
SP - 5404
EP - 5412
JO - polymer
JF - polymer
IS - 23
ER -