ABSTRACT
As it is known [1], semicrystalline polymers, similar to widely applicable polyethylene and polypropylene, at temperatures of the order of room ones have devitrificated amorphous phase. This means that such phase elasticity modulus is small and makes up the value of the order of 10 MPa [2]. At the same time elasticity modulus of the semicrystalline polymers can reach values of ~ 1.0-1.4 GPa and is a comparable one with the corresponding parameter for amorphous glassy polymers. In case of the latters it has been shown [3, 4], that they can be considered as natural nanocomposites, in which local order domains (nanoclusters) serve as nanofiller and as loosely packed matrix of polymer within the framework of the cluster model of polymers amorphous state structure [5] is considered as matrix. In this case elasticity modulus of glassy loosely packed matrix makes up the value of order of 0.8 GPa and a corresponding parameter for polymer (e.g., polycarbonate or polyarylate) ~ 1.6 GPa. In other words, the reinforcement degree of loosely packed matrix by nanoclusters for amorphous glassy polymers is equal to ~ 2, whereas for the semicrystalline polymers it can exceed two orders. By analogy with amorphous [3, 4] and cross-linked [6] polymers semicrystalline polymers can be considered as natural hybrid nanocomposites, in which rubberlike matrix is reinforced by two kinds of nanofiller: nanoclusters (analog of disperse nanofiller with particles size of the order of ~ 1 nm [5]) and crystallites (analog of organoclay with platelets size of the order of ~ 30-50 nm [7]). The clarification of abnormally high reinforcement degree mechanism allows giving an answer to the question, would this mechanism be applicable to polymer nanocomposites, filled with inorganic nanofiller (e.g., organoclay). Therefore, the purpose of the present work is the study of reinforcement mechanism of rubber-like matrix of high-density polyethylene (HDPE) at its consideration as natural hybrid nanocomposite.
