Carboxyl functionalised MWCNT/polymethyl methacrylate bone cement for orthopaedic applications.
The incorporation of carboxyl functionalised multi-walled carbon nanotube (MWCNT-COOH) into a leading proprietary grade orthopaedic bone cement (Simplex P™) at 0.1 wt% has been investigated. Resultant static and fatigue mechanical properties, in addition to thermal and polymerisation properties, have been determined. Significant improvements (p ≤ 0.001) in bending strength (42%), bending modulus (55%) and fracture toughness (22%) were demonstrated. Fatigue properties were improved (p ≤ 0.001), with mean number of cycles to failure and fatigue performance index being increased by 64% and 52%, respectively. Thermal necrosis index values at ≥44℃ and ≥55℃ were significantly reduced (p ≤ 0.001) (28% and 27%) versus the control. Furthermore, the onset of polymerisation increased by 58% (p < 0.001), as did the duration of the polymerisation reaction (52%). Peak energy during polymerisation increased by 672% (p < 0.001). Peak area of polymerisation increased by 116% (p < 0.001) indicating that the incorporation of MWCNT-COOH reduced the rate of polymerisation significantly. A non-significant reduction (8%) in percentage monomer conversion was also recorded. Raman spectroscopy clearly showed that the addition of MWCNT-COOH increased the ratio between normalised intensities of the G-Band and D-Band (IG/ID ), and also increased the theoretical compressive strain (-1.72%) exerted on the MWCNT-COOH by the Simplex P™ cement matrix. Therefore, demonstrating a level of chemical interactivity between the MWCNT-COOH and the Simplex P™ bone cement exists and consequently a more effective mechanism for successful transfer of mechanical load. The extent of homogenous dispersion of the MWCNT-COOH throughout the bone cement was determined using Raman mapping.
['Ormsby|Ross W|RW|', 'Modreanu|Mircea|M|', 'Mitchell|Christina A|CA|', 'Dunne|Nicholas J|NJ|']
Polymethyl methacrylate bone cement multi-walled carbon nanotube mechanical properties Raman spectroscopy thermal properties