Comparative Study on the Behavior of Virgin and Recycled Polyolefins–Cellulose Composites in Natural Environmental Conditions

Abstract

Polypropylene−cellulose composites have great potential in many important commercial applications, and it is important to understand and properly evaluate their biodegradative behavior to achieve improved composite formulations in accordance with their future applications. In the present study, an outdoor soil burial test was performed in order to evaluate the susceptibility to degradation of polyolefins−cellulose composites. The structural and morphological changes were analyzed by Fourier transform infra-red spectroscopy with attenuated total reflectance (FTIR-ATR) and scanning electron microscopy (SEM). The weight loss of composite samples after burying in soil was recorded. The presence of new bands, as an indicator of degradation, was confirmed by FTIR-ATR spectra. The thermal stability of the composites after soil burial analyzed by TGA was slightly improved, with relatively higher temperatures being required to decompose the samples after exposure to environmental factors. SEM micrographs presented some modifications of the polymer surface, such as holes, cracks, exfoliations, and fractures. Increasing the cellulose percentage of the composite samples led to increased weight loss. From the obtained results, it can be concluded that composites based on polyolefins and renewable resources undergo a slow process of biodegradation after contact with environmental microorganisms and, with appropriate composition, could be applied to various environmental fields.

Keywords

• composites
• microbial degradation
• polyolefins
• virgin or recycled polypropylene