A Uniform Characterisation Of The Particle Size And Particle Size Distribution In Polymer Mixtures

Abstract

Polymer mixtures or blends are playing an increasingly important role in the field of engineering plastics. The way the polymers are intermixed is of extraordinary and dominating influence on the properties of these mixtures.

Generally one of the polymers serves as the matrix into which a second minor proportion of polymer is dispersed in the form of fine particles. The nature of the dispersion and consequently the resulting properties can be influenced by the various processing steps.

It is therefore the relationship between on the one hand particle size or particle size distribution, processing conditions and on the other the properties which should be given the utmost consideration.

To simplify discussions on these phenomena a uniform method has been developed for the determination of the particle size and particle size distribution.

The method essentially consists in measuring scanning electron micrographs of cut surfaces, with a contrast having been introduced to distinguish the various polymer phases with a Quantimet. The two-dimensional information thus obtained can be converted into a particle size distribution by means of a statistical mathematical method.