Dielectric property of modified barium titanate/polyamide 11 nanocomposites with different surfactants

Abstract

Barium titanate/polyamide 11 (BT/PA11) nanocomposites were prepared by modifying BT nanoparticles with dry surface modification process, which had well dispersion, high dielectric constant, and low dielectric loss. Various methods were reported to improve dispersion and compatibility with complex process and high cost. Herein, three surfactants [ γ‐aminopropyl triethoxy silane (KH550), sorbitan monostearate (SP60), and octadecyl phosphate ester (OPE)] were chosen to modify BT nanoparticles. Then modified‐BT nanoparticles were blended with PA11. The structure was characterized by Fourier transform infrared, scanning electron microscope, and wide angle X‐ray diffraction. Dielectric property was studied by broadband dielectric spectroscopy. The frequency dependence and temperature dependence of dielectric constant, dielectric loss, and dielectric modulus were analyzed. In general, dielectric property has strong frequency and temperature dependence. Furthermore, dielectric spectra shows that modified BT/PA11 nanocomposites have higher dielectric constant, lower dielectric loss, fewer interface polarization, and more dipole polarization. In contrast to three surfactants, OPE‐BT nanoparticles have better effects, whose dielectric constant increases from 19 to 28 at 1 Hz, and dielectric loss decreases from 0.36 to 0.23. Meanwhile, mechanical property was characterized by universal testing machine. In all, the work improves dispersion of BT nanoparticles and dielectric property with easy process and low cost. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47447.

Basalt Fiber Modified Ethylene Vinyl Acetate/Magnesium Hydroxide Composites with Balanced Flame Retardancy and Improved Mechanical Properties

“…As can be seen in Figure 1 a, there is an absorption peak at 960 cm −1 on the FTIR curves of the PBF, which can be attributed to Si–OH. The absorption peak at 1066 cm −1 corresponds to the Si–O–Si bond of KH550 grafted BF ( Scheme 1 ) [ 23 ]. Peaks at 2986 cm −1 and 2902 cm −1 are assigned to be antisymmetric and symmetric tensile vibration of the –CH 2 – group in KH550, respectively [ 24 ].…”

Synergistic effect between solid wastes and intumescent flame retardant on flammability and smoke suppression of thermoplastic polyurethane composites

“…The FTIR spectra are further utilized to characterize the phosphorus tailings and fly ash (as shown in Figure ). In Figure A, the broad absorption peaks at 3448 and 1633 cm −1 for fly ash are ascribed to the OH stretching; the peak at 1069 cm −1 corresponds to the Si―O―Si bond . Compared with the unmodified fly ash, the modified fly ash exhibits new peaks at 2926 and 2858 cm −1 which can be attributed to antisymmetric and symmetric stretching vibrations of ―CH 2 and ―CH 3 groups .…”

“…In Figure 2A, the broad absorption peaks at 3448 and 1633 cm −1 for fly ash are ascribed to the OH stretching; the peak at 1069 cm −1 corresponds to the Si-O-Si bond. 32 Compared with the unmodified fly ash, the modified fly ash exhibits new peaks at 2926 and 2858 cm −1 which can be attributed to antisymmetric and symmetric stretching vibrations of -CH 2 and -CH 3 groups. 33 Moreover, the peak at 1069 cm −1 which is mainly caused by Si-O-Si bond has become stronger, further indicating the presence of KH550.…”

Synergistic effect between phosphorus tailings and aluminum hypophosphite in flame‐retardant thermoplastic polyurethane composites

“…The FTIR spectra of PT are presented in Figure A, the broad absorption peak at 3448 and 1633 cm ‐1 for PT are ascribed to the OH stretching, the peak around 1100 cm ‐1 is corresponded to Si‐O‐Si bond . For the modified PT, the characteristic peak at 2874 cm ‐1 is attributed to the stretching vibration of ‐CH 3.…”