Carbon derived from waste PET as a reinforcing filler in maleated-polypropylene composites

Abstract

The objective of this work is to develop and evaluate maleated polypropylene (MPP) composites reinforced with carbon derived from the pyrolysis of waste PET. It promotes recycling, reduces costs, enhances material properties, and supports the development of sustainable composites. Maleated polypropylene (MPP) and different weight percentages of carbon were melt-mixed, and the similar ATR-FTIR spectral peaks observed for both MPP and MPP/carbon composites suggest that the interaction is mainly physical. SEM analysis showed that the carbon filler is fairly well dispersed throughout the MPP matrix. Although the carbon filler encourages crystallization in MPP due to its nucleating effect, the overall degree of crystallinity decreases significantly as the carbon content varies from 0 to 30 wt. % (80.9 to 40.3). Rheological studies indicated that the storage modulus reaches its maximum at carbon loadings between 2.5 and 10 wt. %, then declines at higher filler levels but remains above that of pure MPP. The loss modulus is highest at lower carbon loadings and gradually decreases with increasing carbon content. The tensile strength of the composites increases with carbon loading from 2.5 to 10 wt. % (24.8 MPa to 27 MPa), then declines at higher filler concentrations (27 MPa to 25.8 MPa). The tensile modulus increases with rising carbon content from 0 to 30 wt. % (1.3 GPa to 1.75 GPa). The thermal conductivity of the composites rises proportionally with the carbon content, from 0.281 to 0.3434 W/mK.