Multistage wet grinding of talc: relation between physico-chemical parameters of the filler and mechanical properties of filled polypropylenes

Abstract

Three talc samples of different mineralogical composition were wet-ground with an increasing number of grinding cycles. On each sample the particle size analysis, X-ray diffraction spectra, infrared spectra and nitrogen adsorption isotherms were carried out. In parallel, three mechanical properties of talc-filled polypropylenes were determined. A statistical analysis based on normalized principal component analysis and multiple partial linear regression was then carried out in order to determine correlations between the physico-chemical parameters of the fillers and the mechanical properties of polypropylene composites. The results show that this approach is valid only if the samples are separated according to their mineralogical composition. On the basis of this first analysis, an “industrial” model based on easily obtainable parameters is proposed. It is very satisfactory for talc-rich samples. For more chloritic ores, some other parameters have to be measured to enhance the quality of the models. The approach proposed in the present study seems then very promising.