The influence of the structure of starch on the mechanical, morphological and thermal properties of poly (ε-caprolactone) in starch blends

In this work, the influence of three starches (A1, A2 and A3) on the mechanical, morphological and thermal properties of poly(ε-caprolactone) (PCL) was investigated in PCL/starch blends of 0/100, 75/25, 50/50 and 25/75 w/w%. The addition of starch to PCL reduced the tensile stress at break, the elongation at break and Young’s modulus. The starches with linear chemical structures (A1 and A3) had lower values of tensile strength and higher values of elongation at break. Light microscopy indicated that the starches and PCL were immiscible. Thermal analysis showed that the 75/25, 50/50, and 25/75 w/w% blends containing linear starches had greater crystallinity than branched starch, an arrangement that may favor their biodegradation.