Regarding to the extrusion process parameters, it has been noted that higher feed rates, lower screw speeds and narrower kneading blocks have reduced the ductile-brittle transition temperature (DBTT) of the compatibilized
PBT/ABS blends, thereby suggesting that the molecule integrity of blend polymeric components has been preserved and that a good dispersion of the ABS domains in the PBT matrix has been achieved. Injection molded PBT/ABS blends were obtained to compare to the extruded ribbons. The mechanical tests for both specimens have shown the same trends. The injection molded samples have presented poorer impact strength, tensile strain at break and tensile strength, when GM6001 inhibitor compared to the respective extruded samples. That behavior has been attributed to the high level of molecular orientation resulting from the injection molding process and mainly to PBT degradation Elafibranor chemical structure during process. The PBT degradation could have increased its degree of crystallinity, which has been confirmed by DSC measurements. As result, the blend became more brittle, decreasing its Izod impact strength. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012″
“We investigated numerically and experimentally the transmission of terahertz (THz) waves through single and multiple metallic defects
created in a one-dimensional (1D) photonic crystal (PC) by inserting single metallic wires or arrays of parallel metallic wires into the air-gap defect of the 1D PC. The transmission properties of the metallic defect modes generated in the photonic bandgap (PBG) were characterized by using THz time-domain spectroscopy. For single metallic defects, it was found that the appearance the defect mode depends not only on the diameter of the metallic wires but also on the polarization of the THz wave. For transverse magnetic (TM) polarized waves whose electric fields are parallel to the metallic wires, the incident THz wave is generally split into two identical parts. In sharp contrast, the excitation of surface plasmon polaritons (SPPs) P5091 with enhanced
field intensity is observed for transverse electric (TE) polarized waves whose electric fields are perpendicular to the metallic wires. In both cases, two resonant modes with reduced transmittance are observed in the PBG. While the resonant mode related to SPPs is found at the long-wavelength side of the original defect mode, the resonant mode without the excitation of SPPs appears at the short-wavelength side. Numerical simulation based on the finite-difference time-domain (FDTD) technique revealed that the electric field of SPPs is more tightly confined at the surface of the metallic wire when it is placed in the PC, implying that the confinement of a THz wave in the propagation direction will facilitate the localization of SPPs in the transverse direction. For two parallel metallic wires, the defect mode was found to depend on the separation between them.
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