A.A. ROGACHEV, М.А. YARMOLENKO, P.A. LUCHNIKOV, A.V. ROGACHEV
The nanocomposite polymer coatings formed by plasma chemical methods are characterized by a range of structural peculiarities. The presence of a fine-grained filler inside a polymer coating, its nature, various external effects influence the character and kinetics of the structural changes. The research of these processes is of practical and scientific interest.
The main aim of the research is to study molecular structure, morphology of thin composite metal-polymer and polymer-polymer coatings on the basis of polyethylene (PE) formed from the active gas phase, to determine the peculiarities when they are influenced by heat treatment of the formed layers.
The polymer composite coatings have been produced from the active gas phase generated by electron-beam dispersion of the mechanical mixture of the powders: while depositing polymer-polymer coatings – polyethylene and polytetrafluorethylene (PTFE); while depositing metal-polymer coatings – PE and metal organic compounds. In particular cases low-frequency (f = 1000 Hz) glow discharge inside the camber, in the flame of dispersed volatile particles, has been produced to give additional activation to the products of electron-beam dispersion. Current density of discharge is j ≈ 0,6 А/m2.
The annealing of the coatings has taken place in vacuum for an hour at the temperature 120 оС.
The molecular structure has been defined by the methods of infrared spectroscopy, the morphology – by the methods of scanning probe microscopy.
The molecular and morphological peculiarities of thin composite metal-polymer and polymer-polymer coatings on the basis of polyethylene formed from the active gas phase have been worked out experimentally as well as the laws of influence of the conditions and the regimes of heat treatment on them. It has been stated that the introduction of metals leads to the crystallinity reduction in the formed polyethylene composite coating, changes ratio of the unsaturated double bonds in its molecular structure. The influence of the nature of metal nanoparticles on the development processes of molecular structure and morphology of particles has been determined. The most significant structural changes of the polymer matrix occur while introducing atoms of chromium (in comparison with nickel and lead). This can be explained by the interaction of the metal with the molecular particles of polyethylene. The development of the layer structure in metal-polyethylene coatings has been stated after the process of annealing in vacuum.
While annealing nanocomposite layers of PE – PTFE it is possible to observe the content reduction in the unsaturated double bonds and crystallinity of the polyethylene component, defects attenuation in the fluoroplastic component of the composite coating. The character of changes in molecular structure is also influenced by the conditions of deposition, the presence or absence of plasma activation of volatile products.