The structural treatment of amorphous glassy polycarbonate as natural nanocomposite was proposed. It has been shown that the polycarbonate stiffness is defined completely by the state of its structure, which is described within the frameworks of a local order model. The large reserves of stiffness raising for amorphous glassy polymers are demonstrated.
The investigation of fullerenes and especially of carbon nanotubes (CNTs) has opened a totally new window for the development of polymer matrix composites with novel properties and applications. CNTs, which have a number of unexpected properties, both mechanical and electrical, seem to have huge potential as a filler, i.e. as a reinforcement in nanocomposites. With the discovery of carbon nanotubes, the research efforts have been initially concentrated on the better understanding of their processing conditions, modification, and properties.
Silica was compared with clays as supports for metallocene. Ethylene homopolymerization with both homogeneous and heterogeneous catalysts was performed. Activation energy was higher for
(n-BuCp)2ZrCl2/SiO2/MAO, although high activities were obtained for catalysts with clay. They showed Ea close to that of homogeneous precursor. Catalyst/clay control polymer morphology until 363 K
The complete similarity of reinforcement degree behaviour has been shown for nanocomposite epoxy polymer/Na+-montmorillonite and polyarylate, which is considered as the natural nanocomposite. The polyarylate structure description is given within the framework of cluster model of polymers amorphous state structure. The interfacial adhesion level influences strongly the reinforcement degree of indicated materials.
A quantitative structural model of particulate-filled polymer composites impact toughness, based on the fractal analysis ideas, was offered. The model demonstrated good correspondence with the experimental data. It has been shown that the action of nanofiller as nucleator, resulting in crystallinity degree and amorphous phase structure change, exert the main influence on impact toughness value.
The treatment of amorphous glassy polymers as natural nanocomposites is proposed. It has been shown that the geometry of intercomponent interactions nanoclusters – loosely-packed matrix defines adhesion level between the indicated components of natural nanocomposites. Since nanoclusters – loosely-packed matrix contact is realized over cylindrical surface of the first ones then the larger the indicated surface area the higher the intercomponent adhesion level.
It has been shown that two types of nanofiller aggregation processes are realized during polymer/carbon nanotubes nanocomposites production: formation of nanotubes ropes and their bending. The first one from the indicated processes is realized at carbon nanotubes contents larger than the percolation threshold. The ultrasound affects only carbon nanotubes aggregation of the second type.
The most typical behaviour features of polymer nanocomposites filled with dispersed calcium carbonate were considered. The quantitative analysis was carried out within the frameworks of structural model: the cluster model of polymers amorphous state structure and fractal analysis. It has been shown that all changes of the considered nanocomposites properties were defined by polymeric matrix structure variations, which are due to nanofiller introduction.
It has been shown that aggregation (tangled coils formation) of carbon nanotubes begins at their very small contents. This factor strongly reduces reinforcement degree of polymer/carbon nanotube nanocomposites. Estimation of the main parameters that influenced elasticity modulus of the mentioned nanocomposites was fulfilled. Theoretical calculations showed high potential of nanocomposites filled with nanotubes.
It has been shown that permeability to gas coefficient reduction at the layered nanofiller introduction in polyethylene is due to polymer matrix fraction decrease, which is accessible for gas transport processes. Two models (percolation and multifractal ones) are offered for this reduction quantitative description.