Effect of functionalized polymer modifiers on structure and mechanical properties of degraded low-density polyethylene
Fariz Amirov, Ibragim Movlaev, Khayala Seyidova
Quarterly No. 2, 2026 pages 97-105
DOI: https://doi.org/10.62753/ctp.2026.05.2.2
keywords: polyethylene, sulfochlorinated atactic polypropylenes, chlorinated atactic polypropylenes, composite materials
abstract This paper investigates the influence of functionalized polymer additives—sulfochlorinated atactic polypropylene (SCAPP) and chlorinated atactic polypropylene (CAPP)—on the structural, mechanical, and rheological properties of composite materials based on recycled low-density polyethylene (RLDPE). Waste polyethylene was collected from the Gazakh and Aran regions of Azerbaijan, and the additive content ranged from 5 to 20 weight mass. The composites were prepared by melt blending in a laboratory twin-screw extruder at temperatures of 170–180°C. The results show that the incorporation of functional additives improves phase compatibility, enhances thermal stability, and increases the mechanical strength of the material. Rheological analysis revealed that the melt flow index (MFI) of RLDPE grows with increasing temperature and applied load, but decreases with increasing content of the second component in binary mixtures with CAPP or SCAPP. Three-dimensional plots constructed at 130°C, 150°C, and 170°C confirm this relationship. The optimal SCAPP content provides improved melt flow behavior in the range of 150–170°C, indicating enhanced processability of RLDPE. The highest MFI values were observed at 170°C, which is associated with reduced melt viscosity. Mechanical testing showed that the addition of 5–10 weight mass CAPP or SCAPP raises the tensile strength and elongation at break, while an additive content of 15 weight mass ensures optimal mechanical stability. Modification with CAPP improves the properties of RLDPE by approximately 80–86%, whereas SCAPP exhibits a slightly lower effect due to the presence of sulfur-containing groups. Furthermore, the addition of 5–7 weight mass CAPP to binary systems containing mineral fillers such as sludge and zeolite enhances both mechanical and thermal properties while maintaining an effective viscosity of 9–11 Pa·s.