Processing UHMWPE-CNTs

Regarding to mechanical properties, it was reported the fabrication of UHMWPE/CNTs composites with properties close to the commercially available fibers like Kevlar [63]. Bakshi et al. [64] used a quite different technique to prepare films of UHMWPE/CNTs. Mechanical ball-milling to mix the raw UHMWPE with CNTs, and after that the powder composite was processed by compression molding in a hot press. The results have shown a homogeneous distribution of the CNTs into the UHMWPE. Xue et al. 

The main advantage of this method is that it enables grafting of the polymer macromolecules onto the sidewall of the CNTs. This technique is particularly important for the preparation of insoluble and thermally unstable polymers, which cannot be processed by solution casting or melt mechanical mixing. In situ polymerization can be applied for preparation of almost any CNT-polymer nanocomposite, which can be non-covalently or covalently bound to polymer matrix. Kaminsky et al. [53] prepared UHMWPE/ CNTs nanocomposites by in-situ polymerization using metallocene, and investigated the influence of the CNT concentration in the thermal... 

Although there are several compounds (Ascorbic acid (vitamin C) or alpha-tocopherol (vitamin E) which their antioxidant effect is proved to be effective in reducing the oxidation of UHMWPE [60], there are several studies that support the antioxidant capacity of carbon nanotubes (CNTs). For example, in the study of Zeynalov et al. [61] was conducted a simulation of thermo-oxidative processes which take place in the polymer chains, and the results showed an inhibition of oxidation of the polymer when carbon nanotubes are present. Also, P. Castell et al. [62] founded that the incorporation of low concentration of arc-discharged multiwall carbon nanotubes (MWCNTs) can act as inhibitors of the oxidative process on irradiated UHMWPE, proving the radical scavenger effect of this reinforcing material. Also, this study shows that the presence of MWCNTs enhances the chemical stability of the polymer. 

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