Coupling Agents and Fibre Chemical Treatments

In lignocellulosic fibres, several chemical pretreatments performed before compounding have been investigated by a number of researchers showing potential to remove waxes, oils from the surface and make 

These results make LDHs excellent candidates as fillers for polymer matrices, to be used as degradant additives, which permits a precise control of the lifetime of the plastic product, decreasing its negative impact on the environment. The improvement in the thermal properties of PE/LDH nanocomposites is usually explained assuming that the LDH layers act as a sort of barriers. Yue et al. [56] claim formation of nanostructures from the dispersed LDH particles, which decrease heat transfer, thus stabilizing the polymer chains. Dispersion of the LDH particles thus improves the barrier properties of the polymer nanocompounds because of their easy exfoliation. Fluid diffusion, especially gases, is strongly affected by this barrier effect. 

6 Ultra High Molecular Weight Polyethylene and its Reinforcement/Oxidative Stability with Carbon Nanotubes in Medical Devices 

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. 

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. 

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