Investigation on the effects of simultaneous adding of α -tocopherol (vitamin E) and Multi-walled carbon nanotubes (MWCNT) on the mechanical properties and biocompatibility of the ultra-high molecular weight polyethylene polymer matrix (UHMWPE)

Ultra high molecular weight polyethylene (UHMWPE) has been used as the material of choice in joint replacement prosthesis for the last three decades due to its excellent physical and chemical properties. However, UHMWPE’s wear and oxidation in the long term leads to osteolysis and limits the lifespan of this polymer. One of the effective methods to prevent oxidation is presents of α-tocopherol in UHMWPE matrix. But the presence of this additive alone does not improve the mechanical performance of UHMWPE. On the other hand, the use of multi-walled carbon nanotubes (MWCNTs) has been shown to improve mechanical properties due to their exceptional properties such as elastic modulus and high surface-to-volume ratio. However, finding the optimal concentration of MWCNTs and vitamin E to improve the mechanical properties of this polymer is very vital and important.

In this research, to investigate and compare the effects of carbon nanotubes on the properties of UHMWPE/vitamin E composite, two composites were produced, one containing 0.2% by weight of vitamin E and the other containing 0.25% by weight of vitamin E along with 0.5% by weight of MWCNT.

Fourier transform infrared spectroscopy (FTIR) reported an increase in the characteristic peaks of PE-E/CNT composite compared to PE-E composite. Differential scanning calorimetry (DSC) reported about 7% increase in crystallinity in PE-E/CNT composite. Dynamic thermos mechanical analysis (DMTA) also showed improved elastic properties in the PE-E/CNT composite compared to the composite containing vitamin E. Finally,