Evaluation of thermal, mechanical and morphological properties of PCL/CA and PCL/CA/PE-g-GMA blends

The use of biodegradable polymers provides an attractive solution to minimize environmental problems caused by the accumulation of waste plastics in landfills. In this study, poly(ε-caprolactone) (PCL) and cellulose acetate (CA) were blended in different proportions (80/20, 60/40, 40/60 and 20/80 PCL/CA, w/w) and the influence of adding polyethylene-graft-glycidyl methacrylate (PE-g-GMA) as a compatibilizer was investigated by assessing the thermal (differential scanning calorimetry, DSC) and mechanical (tensile strength, elongation at break and Young's modulus) properties of the blends. The morphology of the polymers was also examined by scanning electron microscopy (SEM). The incorporation of PE-g-GMA reduced the crystallinity of PCL and increased that of the 80/20 and 20/80 blends, in which this polymer promoted reorganization of the PCL chains. In contrast, PE-g-GMA did not alter the crystallinity of the PCL on 60/40 and 40/60 blends. The addition of PE-g-GMA increased the tensile strength of pure PCL and the 40/60 blend, but reduced the tensile strength of CA. PE-g-GMA also increased the elongation of PCL and the 80/20 and 60/40 blends, reduced the elongation of pure CA and the 20/80 blend, and increased the rigidity of the polymers. SEM showed that PE-g-GMA increased the dispersion of PCL, indicating greater interaction between the polymeric chains.