In converting biomass to bioenergy through thermochemical processes, a considerable amount of solid residue generates in each conversion cycle (up to 35 wt.%) which mainly consists of renewable carbon (biocarbon). However, the biocarbon is considered as a byproduct of the pyrolysis units. Unless a high-volume application exists for the biocarbon, the significant amount of this byproduct can challenge the long-term sustainability of pyrolysis units. In this project, biocarbon is intended to be used as filler in plastic industry targeting toughened polypropylene (PP) based automotive parts. In order to achieve a suitable balance of mechanical properties, biocomposites were compatibilized using a maleated polypropylene. Furthermore, the PP phase was nucleated using a Î² nucleating agent to increase the impact toughness without significant loss in the stiffness. Tensile properties and notched Izod impact strength were measured as response variable. Atomic force microscopy (AFM) was utilized to analyze the PP-biocarbon interface in presence and absence of the compatibilizer. The effect of the nucleating agent was investigated by differential scanning calorimetry (DSC) and correlated to the improvement of biocomposites impact toughness. The results suggest that the morphological changes caused by the compatibilizer and toughening effect of Î² crystals can generate high impact toughness in composites with 20 wt.% loaded biocarbon. Therefore, the biocarbon can be utilized in high loading levels similar to current petroleum-based composites with comparable mechanical properties. At the end, substituting conventional mineral filled composites with biocarbon-based biocomposites can provide the required mechanical properties with added benefits of lower density (â15%), 30% higher bio-based content and cheaper price. These benefits would translate into improved fuel economy of cars and reduction in greenhouse gas production. Considering the high-volume usage of plastic parts especially in automotive industry, this approach would make the biomass to bioenergy conversion more sustainable.
Keywords: Biocarbon, Toughened biocomposites, Polypropylene.
Acknowledgement: We gratefully acknowledge the financial support of the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)/University of Guelph - Bioeconomy for Industrial Uses Research Program Theme Project # 030055; Ontario Research Fund, Research Excellence Program; Round-7 (ORF-RE07) from the Ontario Ministry of Research, Innovation and Science (MRIS) (Project #052644 and 052665), and the Natural Sciences and Engineering Research Council (NSERC), Canada Discovery Grant Project # 401111 to carry out this research work