Recycling of Polypropylene with Vitamin E Additives: Rheological Properties and Mechanical Characteristics

Polypropylene (PP) is a highly sought-after synthetic polymer. Due to its properties, it has wide applications in a number of industries. One-dimensional molded materials (fibers and strands) are widely used in the textile and construction sectors. Concrete reinforcing using PP fiber is an intriguing use in construction. Fiber can be provided in two forms: fine fibers (microfiber) and extrudates (macrofiber). The macrofiber has a length of up to 60 mm and a thickness of up to 300 microns. The aim of the work was to obtain PP-based macrofibers from recycled polymer using the natural antioxidant tocopherol. The initial polymer is used to produce the fiber, whereas, in this work, it is proposed to use a secondary PP. Vitamin E, a natural antioxidant, was added to the system to stabilize the melts. It has been demonstrated that adding up to 0.5% Vitamin E reduces the heat degradation of the polymer and yields melts with the appropriate viscoelastic characteristics. Rheological data was used to determine the fiber’s formability window. Macrofibers were derived from melts with varying histories. Their structure was investigated using X-ray structural analysis and IR spectroscopy, and their mechanical characteristics were assessed.