Synthesis and properties of new polyamide/multiwalled carbon nanotube nanocomposites containing a pyridine group

Abstract

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.

Structure and properties of buckypapers based on poly(methyl methacrylate-co-methacrylic acid)/ polyamide 6,6 and carbon nanotube intercalated montmorillonite

“…The HRR curves of the reported polyamide-CNT nanocomposites have shown the lowering of value to 10.7 W/g. 33 In another attempt, the calculated total heat release per unit surface area was 28 MJ/m 2 for PA6 and 27 MJ/m 2 for PA6/clay (2%) composites. 34 The PHHR value for polyethylene/clay nanocomposites was found to decrease to 1340 kW/m 2 .…”

“…According to Mahmood et al, 32 polyamide-6 (PA6) and amine-functionalized CNT depicted thermal degradation behavior in the range of 430-630 C. Whereas neat PA6 showed degradation at $450 C. Similarly, the effects of MWCNT on the thermal properties of a polyamide derived from glutaric acid and aromatic diamine were investigated. 33 The…”