Structural Aspects of Adhesion in Particulate-Filled Polymer Composites

Structural Aspects of Adhesion in Particulate-Filled Polymer Composites 

This chapter considers a study of two types of composites based on polyhydroxyether and graphite with various amounts of a filler. Using various methods it is possible to estimate the adhesion characteristics and interfacial layer, including its thickness and tensile strength and the interdependence between these values and the adhesion properties. The results were treated on the basis of the theory of irreversible aggregation, cluster theory of the polymer structure and fractal analysis. It was established that all the important characteristics of adhesion, the interfacial layer and mechanical properties are interconnected by the fractal dimensions of the surface of the aggregates of filler particles and of the polymer matrix, whose structure is distorted under the influence of the filler surface. 

Adhesion at the interface of the polymer-solid is a determining factor for the physical and mechanical properties of polymer composites. Many properties of particulate-filled composites are determined by the adhesion level at the filler-matrix interface. The problems involved in adhesion are very complicated and adhesion cannot be described by any single theory [1]. Many properties of particulate-filled composites are determined by the adhesion level at the filler-matrix interface [2]. However, no theory allows calculation of the adhesion strength of joints from the data on the nature of substrate and polymer or reliable calculation of the energy of the adhesive interaction. The reason for it is the number of factors that influence adhesion [3-9]. 

In the present review, an attempt will be made to consider some of the structural aspects of interfacial adhesion using modern physical models the cluster model of the amorphous structure of polymers [10], fractal analysis [11, 12] and the model of irreversible aggregation [13]. 

Fractal analysis allows consideration of the surface structure of the filler particles, which are characterised by its fractal dimension (d ) and by the self-similarity interval. Because the polymer structure is also described in the framework of the fractal analysis, it becomes possible to consider the interaction between the filler surface and polymer matrix, including the interfacial layers, based on the analysis of their fractal dimensions. Application of the model of irreversible aggregation allows description of the processes of aggregation of the filler particles in a particulate filled composites. This aggregation causes changes 

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Kozlov, G. V. Lipatov, Yu. S. Fractal and structural aspects of adhesion in particulate-filled polymer composites. Composite Interfaces, 2002,9(6), 509-527. 

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