The peculiarity of formation of Ziegler-type catalytic systems prepared using organoaluminum (AlR 3 ) and organomagnesium (MgR 2 ) on the surface of multi-walled carbon nanotubes (MWCNTs) was revealed. We have found first AlR 3 and MgR 2 interact with different sites on MWCNT surface. It was demonstrated by IR spectroscopy that organoaluminum compounds were immobilized on the hydroxylcontaining groups on MWCNT surface. Organomagnesium compounds were immobilized on the topological structural defects of MWCNTs; hydroxyl-containing groups were not required for their immobilization. Further interaction between TiCl 4 and organomagnesium compound immobilized on the MWCNT surface yielded a catalyst containing titanium and magnesium chlorides (an analogue of the known titaniummagnesium catalysts), which exhibits an enhanced activity in ethylene polymerization. The effect of polymerization conditions on molecular weight characteristics of polyethylene in the MWCNT/PE composite material produced by in situ polymerization over the catalyst immobilized on the MWCNT surface was studied.

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The article describes a method of the synthesis of carbon nanofibers (CNFs) and a technique for obtaining masterbatches, which are represented by CNFs with a layer of pre-synthesized polyethylene (PE) on their surface. Using scanning electron microscopy, it was shown that in-situ ethylene polymerization over the catalyst anchored on the CNF surface allow to evenly cover CNFs surface by PE. Pristine and pre-coated CNFs were introduced to commercial PE matrix. It has been found that the reinforcing of PE with CNFs leads to improved mechanical properties and two times higher resistance to abrasive wear. The application of the proposed approach makes it possible to reduce significantly the carbon filler’s effective concentration and distribute uniformly the filler throughout the composite.

Data are presented on the evolution of the morphology of polyethylene (PE) formed via in situ polymerization with different polymer yield over a Ziegler‐type titanium‐magnesium catalyst anchored on the CNT surface. Individual polymer microparticles are formed on the CNT surface at the initial polymerization stage (the yield of 2.5–10 g PE/g CNT) with the formation of PE/CNT composites having a shish‐kebab structure. As the polymer yield increases above 10 g PE per g CNT, the size of microparticles increases and the CNT surface gets totally covered with the polymer. We have found also a great effect produced by the morphology of initial CNT particle aggregates of individual nanotubes on the morphology of macroparticles in PE/CNT composites and the uniformity of CNTs distribution in PE/CNT composites. In the case of CNT samples with a loose structure of macroparticles (aggregates of entangled nanotubes), it is possible to obtain a homogeneous distribution of nanotubes in the polymer matrix of composites and increase the electrical conductivity of composites by 1–8 orders of magnitude by varying the CNT content in the composites from 0.9 to 2.8 wt%.