Enhanced thermal stabilization effect of hybrid nanocomposite of Ni-Al layered double hydroxide/carbon nanotubes on polyvinyl chloride resin

In the work, hybrid nanocomposite of Ni-Al layered double hydroxide (LDH) and carbon nanotubes (LDH/CNTs) was assembled via one-pot hydrothermally assisted coprecipitation approach and applied as the thermal stabilizer in polyvinyl chloride (PVC) resin. Various structural characterizations revealed that smaller LDH nanoplatelets could be uniformly dispersed on the surface of CNTs or closely combined with the CNTs matrix, thus forming unique hybrid nanostructure and strong LDH-CNTs interactions. The thermogravimetry (TGA), Congo red tests, and TG-fourier transform infrared (TG-FTIR) experiments for the PVC-based composites demonstrated that compared with pristine NiAl-LDH and CNTs, as-assembled LDH/CNTs nanocomposite exhibited greatly enhanced thermal stabilization effect on PVC resin. Especially, PVC/LDH/CNTs composite with 5.0 phr of LDH/CNTs additive delivered a superior thermal stabilization effect on PVC to other PVC-based composites, along with the greatly increased maximum degradation temperature and the improved removal efficiency of hydrogen chloride by about 40 degrees C and 64.8%, respectively. It was concluded that through the assembly of NiAl-LDH with CNTs, the enlarged LDH interlayer spacing, enhanced dispersion of NiAl-LDH component in PVC resin, and strengthened interfacial interaction between NiAl-LDH and PVC could account for the improved thermal stabilization effect of LDH/CNTs additive on PVC during the pyrolysis of PVC. (C) 2020 Elsevier Ltd. All rights reserved.