BASALT/POLYPROPYLENE COMPOSITES: THE EFFECTS OF MECHANICAL REPROCESSING ON THEIR MORPHOLOGICAL, THERMAL, RHEOLOGICAL AND MECHANICAL BEHAVIOR
Edited by:
Prof. Fabrizio Sarasini, DICMA, ICI
Dr.ssa Claudia Sergi, DICMA, ICI
Prof. Jacopo TIrillò, DICMA, ICI
Waste generation is a direct consequence of population growth and economic development, therefore accurate waste management policies are needed to meet the 2008/1/EC directive in the field of Integrated Pollution Prevention and Control (IPPC). The transition to a circular economy, which encourages materials reuse and recycling is a fundamental step for most industrial sectors like the packaging and transportation ones, which exploit almost 31.0% and 12.0% of the plastics produced, respectively. Considering thermoplastic composites end-of-life, mechanical recycling is the recycling path characterized by the lowest environmental impact when compared with chemical and thermal recycling. Considering also the increasing spread of basalt fibers on the market as bio-based alternative to glass and the massive use of polypropylene (PP) in the automotive sector, the end-of-life of PP/basalt composites through mechanical reprocessing was addressed. The research activity was carried out in the framework of the European Union - NextGenerationEU project of the National Center for Sustainable Mobility (MOST, https://www.centronazionalemost.it), Spoke 11 - Innovative Materials & Lightweighting, which involves Prof. Fabrizio Sarasini as Work Package (WP) leader of the WP5 focused on polymers and Dr. Claudia Sergi as Fixed term researcher (RTDA). The thermal, rheological and mechanical properties of the composites were investigated and the main relationship between their changes and composites fibers length reduction was disclosed. The composites displayed a decrease in their viscosity for increasing reprocessing cycles and were characterized by an improved flowability compared to the neat matrix at the fifth cycle caused by the Intimate contact between the fibers and the matrix which caused a stronger degradation in the polymer. Concerning the mechanical response, the decrease in stiffness and strength was not directly proportional to Fibers length reduction due to a progressive better orientation of the fibers along the manufacturing direction.
The comparison of the mechanical results obtained with the data available for PP composites reinforced with vegetable fibers allowed to conclude that PP/basalt composites are competitive with this type of composites up to the fifth cycle thus highlighting the potential of this solution in a circular economy perspective.
More Information: https://doi.org/10.1016/j.mtsust.2024.100843
