The Effect of the Aging Process on Selected Properties of Polypropylene Modified by Natural Fillers

Abstract

The purpose of the research was to determine the aging-induced changes in selected mechanical properties and flammability of polypropylene modified with natural fillers (sunflower husk, wheat bran, pine sawdust and talc). The fillers were introduced into polypropylene in a mechanical mixing process (weight content 20%). Samples were obtained with the use of the Allrounder 320 C500-170 laboratory injection molding machine. The aging process under artificial sample conditions was carried out in the laboratory chamber (aging time 0, 60, 120, 240, 360 hours). Tests of mechanical properties included measurements of hardness, impact strength and tensile strength. Flammability tests were carried out with a vertical and horizontal alignment of the sample according to PN-EN 60695-11-10 standard. As a result of the research, a significant impact of the introduction of natural fillers in the form of sunflower husks, wheat bran and pine sawdust on selected properties of polypropylene was demonstrated. A large decrease in impact toughness, a relatively small decrease in short-term tensile strength and an increase in the elastic modulus and stress at rupture caused by the introduction of the natural fillers mentioned were found. A beneficial effect was the relatively small impact of aging on the mechanical properties and flammability of modified polypropylene fillers.

Keywords

• mechanical properties
• polypropylene
• flammability
• natural fillers
• aging effect