Investigation of processing properties of polyamide filled with hard coal

Purpose: The aim of this article is to present the influence of contents and kind of hard coal used as powder filler on rheological properties (viscosity) of polyamide 6. Design/methodology/approach: Preparation of composite of polyamide 6 with hard coal was carried out on laboratory twin screw extruder. Extruded composite was granulated and in this form was used for MFR analysis. Taking into account MFR results viscosity was calculated. The influence of filler content on viscosity was next searched. Findings: Results of research showed that addition of powdered hard coal to polyamide 6 matrix cause pronounced decrease of MFR index. In this way significant increase of viscous flow was observed. It is often observed phenomenon for polymer composite filled with powder materials. Research limitations/implications: It is necessary to carry out the research with surface modified hard coal with coupling agents which provide better adhesion of polymer matrix to filler. Practical implications: Hard coal used as a filler in composites makes it possible to gain new and cheaper polymeric materials with many possible applications. Originality/value: Investigation described in article shows possibility of hard coal application as innovatory filler of polymers. The influence of this filler on rheological properties indicate that processing of these new materials may be accompanied with some problems.