Objectif
The main topic of the project proposed is to understand the fundamental principles and mechanisms of formation of reinforced self-ordered structures at a microscopic level in polymer blends prepared from flexible-chain mesophase polyolefines and polybutadienes synthesized with a new catalyst, an immobilized binuclear metal complex compound (IBMCC), and rigid-chain thermotropic liquid crystalline copolyesters synthesized and optimised especially for this study.
Long-term scientific objectives are guided by the following points:
(i) how to create elevated interactions between the two incompatible polymer components
in a binary blend using in addition to traditional mixing in the melt or in solution a new
approach, polymerization of both polymers in situ with the same catalyst, also in
combination with variation of physico-chemical treatments;
(ii) how to establish both on theoretical and experimental grounds the correlation between the chemical structure of blend components, thermodynamic conditions of the blend.
preparation and ability to form reinforced self-ordered structures.
In order to answer these questions, systematic investigations will be carried out for a few families of polymer blends with elevated interactions (chemical links at interfaces) between incompatible components prepared either by synthesis with a new catalyst IBMCC, or by usual mixing "in solution" and "in melt" but using the modifications by g-irradiation and/or by thermal cross linking with peroxides.
The micro-structure, phase phenomena and temperature behaviour of nascent powders, isotropic films and uniaxially oriented blend samples varying in the way of preparation, chemical structure of components, composition, content of intercomponent chemical bonds, level of dispersity, degree of orientation, are expected to be studied within the framework of the project. The correlation between structure and ability to form reinforced stable phases will be established by a combination of state-of-the-art methods: wide- and small-angle X-ray analysis in a wide temperature range, optical and electron microscopy, Raman-, FT-IR- and NMR-spectroscopy, DSC, mechanical tests, density measurements and additional methods.
From the main concept of the project proposed and the choice of blend materials prepared from simple high-a-polyolefines, some polydienes and wholly aromatic and borane containing copolyesters one can expect that the study will not only lead to new knowledge in the chemistry and physics of polymers as a whole, but will also confirm and indicate the conditions for formation of reinforced self-ordered structures at a microscopic scale in binary polymer blends.
Such data are needed to begin systematic theoretical consideration of the semi-ordering processes, which, according to current theoretical predictions, might be developed in such materials.
The practical significance of the research work proposed is apparent. Concerning the polyolefine and polydiene blends prepared using the new catalysts, the development of a novel approach to the problem of control of micro- and macro- structures of these materials, which are an important industrial class of polymer thermoplastics and elastomers, is expected. The elevated activity of the nontraditional catalysts leads, in particular, to a several fold decrease in their consumption, and, as a consequence, to a decrease of heavy metal pollution of the environment. In addition, at this time, one cannot predict, but expect, elevated mechanical characteristics in the blends where the polymer matrix is reinforced by extended-flexible-(carborane containing) or persistent-rigid-(wholly aromatic) chains of the dispersed copolyester at a microscopic scale.
Thème(s)
Appel à propositions
Data not availableRégime de financement
Data not availableCoordinateur
01069 Dresden
Allemagne