The effects of multiwalled carbon nanotubes (MWCNTs) on the thermal properties and flame retardancy of a new polyamide (PA) derived from glutaric acid and aromatic diamine were investigated in this work. The synthesized PA containing pyridine and trialkylamine groups was characterized by 1 H NMR and SEC. The PA unit structure was geometrically optimized at the B 3 LYP/6-311 ++ G(d, p) level of theory. PA showed a glass transition temperature of 151 • C. PA nanocomposites containing two different amounts of MWCNTs were prepared via the solution intercalation technique with the solvent N,N-dimethylacetamide. Transmission electron microscopy showed that MWCNTs were exfoliated in the polymer matrix, resulting in well-dispersed morphologies at 3 wt% MWCNT content. The redox behaviors of PA and the nanocomposites were examined using cyclic voltammetry (CV). PA showed a reversible oxidation process in the CV scan. Thermal and flammability properties of the nanocomposites were studied by TGA in nitrogen and air, DSC and with a microscale combustion calorimeter. The TGA results showed that the addition of MWCNTs resulted in a substantial increase in the thermal stability and char yields of the nanocomposites compared with neat PA. The heat release rate and total heat release were significantly reduced in the presence of MWCNTs.
ABSTRACT. New series of olefinic poly(ether-amide)s (OPEA)s 6a-f was synthesized from 4,4′-bis(1,4-diphenoxybutane)diacrylic acid 4 and aromatic diamine 5a-f via a direct polycondensation reaction. The resulting polymers were characterized by Fourier transform infrared spectra (FTIR), nuclear magnetic resonance ( 1 H-NMR), solubility test and inherent viscosity. The thermal properties of the polymers 6a-c were investigated by thermogravimetric analysis (TGA). Polymer 6c due to presence of SO2 group as a polar group shows better thermal properties compare with polymer 6a and 6b.
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