Mandarin peel as an auspicious functional filler for polymer composites

This work describes the mandarin peel (MP) application as a waste filler for high-density polyethylene (HDPE) composites. The main goal was to investigate the impact of filler’s essential oils, which include multiple terpenes and terpenoids, on the processing, physicochemical, mechanical and thermal properties, as well as color and volatile organic compounds emissions from the composites with different filler content (1-10 wt%). At small loadings, MP can be considered an efficient filler for wood-polymer composites, enhancing their flowability, tensile strength and thermal stability. Besides, it may act as colorant and aroma compound for polymer materials, and enhances the termooxidative resistance of composites. The oxidation induction time was elongated from 20 min for HDPE up to 62 min for the composites with 10 wt% of filler. The obtained research results allow application of the MP not only in the production of highly-filled composites, but also as an additive that significantly enhances the composites’ performance at low concentrations.