Transition Layer in Composites with a Plasticized Filler and Its Influence on the Strength Properties

Composite structures consisting of an epoxy resin matrix filled with a porous perlite containing a finely dispersed polyvinyl chloride are investigated. Models of the composites are analyzed in which the formation of a transition layer between the filler particles and the matrix may arise as a result of interaction between the separate components. The influence of the perlite and plasticized polyvinyl chloride particles on epoxy composite characteristics, such as the bending, tensile, impact, and adhesion strengths, are studied.     

Effect of dispersed filter particles on the strength behavior of composites

An attempt is made to find a solution by which the effect of neighboring filler particles on the strength of composites could be indirectly estimated. The stresses in composites with a great amount of filler are calculated. Composites based on epoxy-resin binder are tested. A comparison of different models shows that the modified Kerner model reflects only the tendency for the compression strength to change with the degree of filling. The relations between the compression strength and the degree of filling are better described by models allowing for constraint of the plastic deformations of the matrix. However, in this case, the effect of the neighboring particles is not properly taken into account. Translated from Mekhanika Kompozitnykh Materialov, Vol. 35, No. 5, pp. 575–584, September–October, 1999.     

Formation of a transition layer on the fillers of polymer composites

Based on a plane model of composites, the effect of a transition layer on the elastic modulus E_c of the composites is analyzed in the case where, under the action of a load, the transition layer is formed both on the side of matrix and filler. In evaluating E_c, it is assumed that the elastic modulus in the layer grows linearly from the elastic modulus of matrix to that of filler, but pores in the filler are impermeable to matrix macromolecules. Analytic relation ships are found which allow one to determine the volume fractions of the transition layer on the side of matrix and filler if the experimental elastic modulus of the composite is known. These relationships are used to find the magnitude of the layer in epoxy composites with various fillers and to evaluate its effect on the compressive elastic modulus of the composites. __________ Translated from Mekhanika Kompozitnykh Materialov, Vol. 42, No. 5, pp. 693–700, September–October, 2006.