The influence of the dispersion quality on the physical and mechanical properties of pigmented automotive coatings.

Professor Jim Guthrie, Leeds University, UK

This paper concerns the effect of the degree of dispersion and the dispersion quality on the mechanical and the surface properties of coatings. The quality of the dispersion was determined by scanning electron microscopy and by particle size analysis as well as by assessment of various performance criteria.



Surface smoothness and gloss were found to correlate well with the quality of the dispersion. In addition, the mechanical performance also correlated well with the quality of the dispersion. Crack propagation was observed to occur through the matrix in all cases for loadings that were above a specific value. The structure or form of the crack pathway, in samples acquired from coatings that were well dispersed, was different from the pathway observed in the relatively poorly dispersed coatings. The impact of the use of selected additives, on the performance properties of the coatings systems studied, is also considered.