Structure and Properties of Polymer Composites Based on Statistical Ethylene-Propylene Copolymer and Mineral Fillers
The influence of the multi-functional organic structurants and mineral fillers on the structural features and physicomechanical properties of polymer composites based on statistical ethylene-propylene copolymer is reviewed. The principal possibility of improvement of strength characteristics and fluidity of polymer composites in the process of joint use of mineral fillers and ingredients is shown.
In recent years, scientists worldwide have all increasingly been attracted to researches aimed at studying the influence of the structure and composition of mineral fillers on the process of formation of crystalline per molecular organization in polymer materials [1–7]. A unique ability of finely divided particles of minerals to affect the mechanism of occurrence and growth of heterogeneous crystal nucleus in the polymer matrix has been detected in the process of mixing the polymers with the minerals. The latter fact has an essential impact on improving the properties of polymer composites filled with minerals.
The following are widely applied in order to implement a set of measures aimed at changing the mechanical properties of the original polymer matrix:
48processing additives that improve processing conditions.
additives that modify the mechanical properties (structurants, plasti-cizers, reinforcing fillers, etc.).
Therewith the efficiency of simultaneous use of a number of additives has the combined action on the properties of the polymer composite. The mechanism of the existence of the components in the boundary areas of the interphase area is predetermined by the physical and physicochemical forms of interaction existing in the additive-macrochain-filler system [7–10].
There are almost no systematic studies aimed at establishing the effect of multifunctional organic structurants on the structural characteristics and properties of filled polymer composites. The urgency of this problem is that the introduction of the minimum concentrations of organic structurants contributes not only to improving the deformation-strength characteristics of polymer composites, but also significantly facilitates the miscibility of the blend components and, as a consequence, their processability [11, 12].
We have repeatedly confirmed in our works [8–12] that the use of organic structurants significantly affects the formation of finely-divided spherulitic structures that contribute to the improvement of the technological compatibility of limited-compatible polymers , increasing the strength properties, melt flow index and processability of composite materials .
Investigations on the effects of finely-divided particles of the organic structurants on the mechanism of formation of per molecular structures in polymer composites and processes occurring in the interphase area and boundary areas of the polymer-filler system still remain open. The occurrence of certain structures in the filled polymers and the consequential impact of filler on the regularity of the changing of their properties are one of the most important criteria predetermining the degree of “strengthening” of the polymer base. The increase in the elasticity coefficient and strength of the samples by dispersing the filler is considered as a form of “strengthening” of polymer composites.
Taking into account the complexity and the insufficient illumination of this problem in the literature, the purpose of this paper is to show how essential the role of multi-functional structurants in the regularities of changes of main physicomechanical and rheological properties of filled polymer composites is.