Natural freshwater degradation of polypropylene blends with additives of a distinct nature

Abstract

Polypropylene (PP) is one of the most widely used polymers in the world, mainly due to its versatility, good properties and low cost. However, as it does not easily degrade in the natural environment, several research projects have been developed in order to increase its biodegradability. The use of pro-degrading additives has been explored, as they promote the polymer degradation process. However, few studies have evaluated the degradation of these materials in natural aqueous environments such as rivers and lakes, which contain large amounts of PP residues. Thus, the present work aims to evaluate the influence of different additives on the degradation process of PP in natural freshwater. Samples from degradation tests were evaluated for 6 months, and their structural, morphological and thermal properties (crystallinity, etc.) were monitored. From the obtained results, it was observed that the additives influenced the degradation of PP. In addition, the enzymatic additive had more promising results since it caused more significant changes in the properties analysed, especially in relation to the morphology and structural characteristics analyses (and consequently the carbonyl index), indicating a greater influence on the degradation process. Thus, the materials studied in this work are an alternative in the field of plastic packaging, reducing the effects caused by plastic waste on the environment.