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.
Показано, що при виробництві нанокомпозитів полімер/вуглецеві нанотрубки реалізовані два типи процесів агрегації нанонаповнювачів, зокрема формування нанотрубних пучків та їх вигин. Перший із зазначених процесів реалізується при вмісті вуглецевих нанотрубок більшому ніж поріг перколяції. Ультразвукова дія поширюється лише на агрегацію вуглецевих нанотрубок другого типу.
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.
Показано, що агрегація (утворення переплутаних клубків) вуглецевих нанотрубок починається при дуже малому їх вмісті. Цей чинник значно понижує ступінь підсилення нанокомпозитів полімер/вуглецеві нанотрубки. Проведено оцінювання основних параметрів, які впливають на модуль пружності вказаних нанокомпозитів. Теоретичні розрахунки показали високий потенціал нанокомпозитів, наповнених нанотрубками.
Запропоновано дві моделі для кількісного опису зниження коефіцієнта газопроникності (перколяційна та мультифрактальна) при введенні шарового нанонаповнювача в поліетилен. Показано, що зниження коефіцієнта газопроникності викликане зменшенням частки полімерної матриці, доступної для процесів газоперенесення.