Mixtures based on polypropylene (PP) and polyamide (PA) are of great importance as structural materials, the mixing of which reduces the negative characteristics of the original polymers. Non-polar PP significantly reduces water absorption of the material during mixing with polar high hydrophilic PA. As a result, the effect of moisture on the mechanical and thermal properties of the composites decreases. On the other hand, mixing PP with PA can extend the temperature range of material exploitation at negative temperatures.
Creation of polymeric nanocomposites based on the polymers of structural designation is a relevant task at present. Of great interest in obtaining the polymeric nanocomposites is montmorillonite, as a nanoscale heterophase.
Optical characteristics of nanocomposite materials have been modeled depends on materials of the nanoparticles and the matrix, the size and shape of nanoparticles. The optical constants of diamond-like carbon films doped with nanoparticles of silver are considered within the framework of the effective theory of Maxwell-Garnett.
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.