Preparation of multi‐walled carbon nanotubes and its application as flame retardant for polypropylene

Abstract

NiO catalyst supported on Fe-pillared montmorillonite (5-15 wt% Ni) was prepared via a simple conventional impregnation method. The physicochemical properties of the Ni catalyst were characterised by X-ray diffraction, inductively coupled plasma-atomic emission spectrometry and transmission electron microscopy. The Ni catalyst, together with organic montmorillonite (OMMT), was employed to prepare multi-walled carbon nanotubes (MWCNTs) by using polypropylene (PP) as a precursor. An increase in Ni loading of the catalyst led to a significant increase in the yield of MWCNTs at the expense of a slight decline in quality of the obtained MWCNTs. Moreover, OMMT altered the degradation process of PP, which resulted in a much higher fraction of light hydrocarbons in degradation products. As such, a substantial increase in the yield of MWCNTs was attained. In addition, the obtained MWCNTs were used as flame retardant for PP, and significantly enhanced thermal stability and flame retardancy according to thermogravimetry analysis and cone data, respectively. PP/MWCNTs nanocomposite exhibited higher degradation temperature, longer ignition time, much lower heat release rate and smoke production rate. This work offers an efficient Ni catalyst to convert PP into MWCNTs which could be applied as flame retardant for polymers.

Layered double hydroxide-oxidized carbon nanotube hybrids as highly efficient flame retardant nanofillers for polypropylene

“…in 1994 21 . Subsequently, several related studies have been conducted 22 23 24 . For example, Kashiwagi et al .…”

Polymethyl methacrylate reinforced with nickel coated multi‐walled carbon nanotubes: Flame, electrical and mechanical properties

“…[ 55–56 ] Similar observation has been made by Shen et al for polypropylene/MWCNT composites. [ 57 ] FPI is the ratio of TTI and pHRR and the combustion time is the difference between TOF and TTI. The FPI values characterize the flame‐retardant effect of materials subjected to fire.…”

Synergetic Effects of Molybdenum and Magnesium in Ni–Mo–Mg Catalysts on the One-Step Carbonization of Polystyrene into Carbon Nanotubes

“…Recently, conversion of virgin or waste plastics into pure and high-valued carbon nanomaterials has received worldwide attention owing to its potential and important supplying to the chemical recycling route currently used waste plastic. So far, many attempts have been done to convert virgin or waster plastics including polyethylene (PE), polypropylene (PP), and polystyrene (PS) into carbon nanomaterials. − For example, Zhuo et al prepared carbon nanotubes (CNTs) by gasification of PE and then catalytic carbonization by a stainless-steel wire mesh . Acomb et al used thermal-cracking fraction of PP, PE and PS as carbon source to synthesize CNTs by Ni/Al 2 O 3 catalysts .…”