# The Impact of Fillers on UV-Aging of Rotomolded Polyethylene Items: A Case Study on Ignimbrite Dust, Arundo donax L. Fibers, and Their Combination

## TL;DR

This study examines how adding ignimbrite dust and Arundo donax fibers to polyethylene affects its UV aging and mechanical properties.

## Contribution

The novel contribution is evaluating the UV stabilization effect of Arundo donax fibers in polyethylene composites compared to ignimbrite dust.

## Key findings

- Arundo donax fibers showed potential to stabilize polyethylene against UV aging.
- Ignimbrite dust at 10% loading increased oxidation in polyethylene composites.
- Filler type and ratio had minimal impact on the mechanical behavior of the composites.

## Abstract

Different composites of polyethylene and two fillers (ignimbrite dust and Arundo donax fibers) were obtained by rotational molding. Both fillers were also combined among them to produce hybrid composites. The blends, prepared by dry-blending, were later rotomolded to determine the effect of such fillers into the tensile properties of the materials, before and after subjecting them to accelerated weathering on a UV chamber for up to 500 h. No significant differences are observed in the mechanical behavior of the different sample series, regardless their type or ratio of filler (5 or 10% by weight), due to the modifications only taking place on the sample surface and the rotomolded items having a thickness of nominally 4 mm. The carbonyl index was obtained from the FTIR spectra, determining an increase in this parameter with irradiation time. The samples with the Arundo fibers exhibit a lower carbonyl index, showing the potential stabilization effect of this lignocellulosic filler against UV, while the composites with the mineral powder tend to increase the oxidation of the samples when included at high loadings (10%).