Characterization of Chemically and Mechanically Treated Recycled Carbon Fibers

Abstract

The increased demand of carbon fiber reinforced polymer (CFRP) in numerous fields has raised concerns regarding its impacts on the environment. Utilization of carbon fiber waste as recovered carbon fibers is a means to reduce these concerns. This study focuses on the recovery of carbon fibers from an aviation composite waste. Initially, recycled carbon fiber reinforced polymer (rCFRP) underwent chemical treatment to eliminate the resin. Then, pulverization process was used to mill the treated fibers into short carbon fibers of about 90 µm. Chemically and mechanically treated individual carbon fibers were successfully extracted from the matrix resin by these treatments. These differently treated carbon fibers were characterized to evaluate their properties. From the scanning electron microscopy images (SEM) observation, chemically treated fibers show minimal damage, while pulverized fibers show rougher surface due to mechanical abrasion. Thermogravimetric analysis (TGA) analysis indicates the chemically treated fiber still contains other elements at about 4 wt%, even after the chemical treatment. From the energy dispersive X-Ray (EDX), it has been identified that these elements consist of oxygen (O), nitrogen (N) and sulfur (S) and phosphorus (P). Moreover, these remaining elements decrease upon undergoing mechanical treatment due to the decomposition and volatilization of organic substances on the rCF throughout the treatment.