ABSTRACT
Keywords ................................................................................................ 51 References ............................................................................................... 51
4.1 THE CRYSTALLIZATION KINETICS OF NANOCOMPOSITES POLYPROPYLENE OR CARBON NANOTUBES
4.1.1 INTRODUCTION
At present, strong enough and diverse changes of polymers crystalline structure occurring at the introduction in them of all sorts of fillers are well-known [1]. As a rule, these changes are described within the frameworks of polymer’s crystalline morphology. However, lately the fractal model has been developed, which takes into consideration the whole complexity of polymers structure. It is assumed that changes occur not only on supramolecular level, but also on molecular and topological levels [2]. It is necessary to take into consideration simultaneously, that crystalline phase morphology variation causes non crystalline regions structure changes [3]. The introduction in semicrystalline polymer inorganic nanofiller results, as a rule, in polymer matrix crystallinity degree increase, since nanofiller particles serve as nucleators. Such effect was observed in nanocomposites high density polyethylene or calcium carbonate (HDPE or CaCO3) [4, 5]. Let us note an important feature of semicrystalline polymers filling: nanofiller introduction can result in both reduction and enhancement of polymer matrix crystallinity degree K. So, the authors [6] found K decrease from 0.72 to 0.38 at carbon fibers introduction in HDPE at its volume content ϕn = 0.303. Therefore, the purpose of present paper is quantitative description of polypropylene crystalline phase structural changes on the above indicated structural levels after the introduction of carbon nanotubes in it.
