A novel approach to the chemical stabilization of gamma-irradiated ultrahigh molecular weight polyethylene using arc-discharge multi-walled carbon nanotubes

• Published in: Journal of materials science Vol. 48; no. 19; pp. 6549 - 6557
• Main Authors: Castell, P., Martínez-Morlanes, M. J., Alonso, P. J., Martinez, M. T., Puértolas, J. A.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.10.2013; Springer; Springer Nature B.V
• Subjects: Analysis; Arc deposition; Ball milling; Carbon; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Crystallography and Scattering Methods; Discharge; Electric arcs; Electron paramagnetic resonance; Electron spin; Infrared spectroscopy; Inhibitors; Irradiation; Materials Science; Molecular weight; Multi wall carbon nanotubes; Nanotubes; Organic chemistry; Oxidation; Polyethylene; Polyethylenes; Polymer matrix composites; Polymer Sciences; Polymers; Radiation; Radiation effects; Radicals; Raman spectroscopy; Solid Mechanics; Spectrum analysis; Spin resonance; Stabilization; Ultra high molecular weight polyethylene; Vapor deposition; Gamma Irradiation; Electron Spin Resonance; Electron Spin Resonance Spectrum; UHMWPE; Ultrahigh Molecular Weight Polyethylene
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-013-7451-1

A complete study was made of the stabilization of gamma-irradiated ultrahigh molecular weight polyethylene (UHMWPE) using arc-discharge multi-walled carbon nanotubes (MWCNTs) as inhibitors of the oxidative process. MWCNTs were efficiently incorporated into the polymer matrix by ball milling and thermo-compression processes at concentrations up to 5 wt% and subsequently gamma irradiated at 90 kGy. Raman spectroscopy demonstrated the generation of radicals on the walls of the MWCNTs and that the G/D ratio was altered by their generation. The same spectra showed interactions between the polymer chains as a series of shifts are observed in the UHMWPE bands. The effect of the MWCNTs as inhibitors for the oxidative process of the UHMWPE was evaluated by means of Electron Spin Resonance (ESR) and Fourier Transformed Infrared Spectroscopy (FTIR). ESR detection of the radiation-induced radicals proved the radical scavenger behaviour of MWCNTs. FTIR measurements were performed to ascertain the influence of the irradiation and of the accelerated ageing protocol in the oxidation index of the polymer and the composites. The results pointed to the positive contribution of the MWCNTs in increasing the oxidative stability of the composite when compared to pure UHMWPE. A comparison is made between composites obtained using MWCNTs produced by the carbon vapour deposition and arc-discharge methods.