Rheological and single screw extrusion processability studies of isotactic polypropylene composites filled with basalt powder. (November 2020)

• Record Type: Journal Article
• Authors: Barczewski, Mateusz; Lewandowski, Krzysztof; Rybarczyk, Dominik; Kloziński, Arkadiusz
• Is Part Of: Polymer testing. Volume 91(2020)
• Publication Date: 2020-11
• Subjects: Rheology -- Extrusion -- Polypropylene -- Basalt -- Composite; Polymers -- Testing -- Periodicals; Polymères -- Tests -- Périodiques; 620.1920287
• DOI: 10.1016/j.polymertesting.2020.106768
• Languages: English
• ISSNs: 0142-9418

Abstract

Abstract: The development of novel composite materials with beneficial mechanical, thermal and electrical properties often focus only on the final properties of the products. However, in many cases their significant application potential may be suppressed by limitations resulting from their rheological and processing properties. The isotactic polypropylene (iPP) composites filled with basalt powder (BP) are known for their good thermomechanical stability and stiffness. The paper presents the complex results of off-line rheological measurements (oscillatory, capillary and torque rheometry) related to processing behavior obtained in a laboratory conditions with the use of a processing machine (single screw extruder), which allow understanding the different manner of the processing behavior occurring during the melt processing of iPP-BP composites. It was found that the addition of BP may cause unusual, beneficial effect of lowered viscosity of the melt. While the addition of up to 5 wt% of BP results in a profitable reduction of the pressure in the barrel during extrusion without influence on the throughput, a higher amount of the filler may lead to significant processing limitations due to strong wall slip. Highlights: Polypropylene (iPP) with basalt powder (BP) composites were manufactured by extrusion. Off-line rheological results were correlated with extrusion processing conditions. Low amounts of BP (5 wt%) caused improved processability of iPP. Unusual rheological behavior of polypropylene basalt composites was found. The addition of BP induced strong wall slip during capillary flow of iPP-BP composites.