Polymer blends of steam‐explosion lignin and poly(ε‐caprolactone) by high‐energy ball milling

Lignin powder, obtained from an abundant and low‐cost source, straw, through a low‐environmental‐impact process, steam explosion, was used for the preparation of blends with a biodegradable polyester, poly(ε‐caprolactone) (PCL), with an innovative technique, high‐energy ball milling. Lignin strongly stabilized PCL against UV radiation. The modulus of the blends increased with the addition of lignin; nevertheless, the elongation at breaking decreased. Through thermal characterization (differential scanning calorimetry and dynamic mechanical analysis), lignin and PCL were found to be immiscible.