Valorization of waste cigarette filters into cellulose acetate fiber-reinforced epoxy composites: Preparation and characterization

Cigarette filters are a major source of persistent polymeric waste arising from the high cellulose acetate content and poor biodegradability. Although the interest in valorizing wastes is increasing, only a few studies have assessed the mechanical properties of cellulose acetate fiber-reinforced epoxy composite materials prepared from the direct use of post-consumer wastes from cigarette filters. In this work, the effects of fiber loading (15 wt%, 20 wt%, and 25 wt%) on the properties of cellulose acetate fiber-reinforced epoxy composite were evaluated. The optimal fiber loading for the composite was found to be 20 wt%, where the tensile strength was 11.5 MPa and flexural strength was 50 MPa, indicating 33% and 117% improvement over the composite prepared from 15 wt% fiber loading. The morphology of the composite was also improved by the intermediate fiber loading content. SEM images show efficient stress transfer from the matrix to the fibers. However, 25 wt% fiber loading resulted in poor composite properties: tensile strength (3.4 MPa), flexural strength (12 MPa), and agglomerated fibers. Impact resistance was found to be inversely proportional to the fiber loading content. The impact energy (4 J) was higher for 15 wt% and 25 wt% fiber loading compared to the 20 wt% fiber loading. Water absorption increased from 4.2% to 13.7% for the composite prepared from 25 wt% fiber loading content. A relationship between the structure and properties was established, indicating the suitability of cellulose acetate fibers from wastes for composite applications.