Polypropylene with powder carbon filler-shungite

Lidia Kurzeja, Edyta Gibas, Stefan Kubica Instytut Inżynierii Materiałów Polimerowych i Barwników w Toruniu, Oddział Zamiejscowy Farb i Tworzyw w Gliwicach, ul. Chorzowska 50A, 44-100 Gliwice, Poland

Quarterly No. 4, 2008 pages 414-418

DOI:

keywords: polypropylene, composites, powder filler, coal, shungite

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abstract The results of studies on the synthesis, mechanical and thermal properties of polypropylene composites with different amount of Shungite III coal filler are present. The shungite rocks contain 1 to 100% C. Shungite is classified by their carbon content as Shungite I (98100% C); Shungite II (8030% C); Shungite III (2834% C); Shungite IV (1020% C) and Shungite V (< 10% C). The rock possesses depending of carbon content sorption, catalytical, bactericidal properties; it is biologically active; it can attenuate and neutralize high frequency electromagnetic emissions. In this study we used Shungite-III, which contains 34% C and 66% inorganic part, mainly silica. The homopolymer isotactic polypropylene (i-PP) as a commercial Moplen HP 540J from Basell Orlen was used. The composites contain: 2.5, 10 and 20 wt. % of filler. Homogenization of the composites and granular preparation were carried out in an internal mixer twin-screw extruder. Granular materials were injection into moulds to prepare specimens for testing. The injecting process was done in modern molding machines. Mechanical properties were measured according ISO. The properties of composites are affected by the properties of its components, the volume fraction of fillers, distribution of the filler into the polymeric matrix and also of the interfacial phenomena between polymer matrix and filler. Thermograms obtained by DSC were done applying heating and then cooling. In this paper we demonstrate small setting changes were observed for small amount of filler (2.5 wt. %), but for greater amount of Shungite filler does not shift peaks of cooling and melting. Mechanical properties of PP filled with coal particles with wide size distribution show a typical behaviour of a particulate filler polymer and generally are compared to the properties of polypropylene filled with mineral fillers especially with calcium carbonate, only elongation at break is unnormal great. Studying the SEM micrograph of the fracture surface of original coal PP, it is obviously that coal particles have induced cavitation. This is the evident of poor adhesion between coal and PP. The cavity led to the brittle fracture and the low strengths.