Corncob arabinoxylan for new materials.

Corncob agricultural waste was used as a source of arabinoxylan for preparation of films. Three arabinoxylan samples were prepared: crude extract (CCAX), purified by a washing step, and purified by bleaching CCAX. Films prepared with untreated CCAX were water soluble, yellowish in color and had poor mechanical properties. After the purification processes the Young's modulus increased from ∼ 293 MPa to ∼ 1400-1600 MPa, and strength was improved from ∼ 9 MPa to around 53 MPa, while the strain at break was kept at ∼ 8% both in untreated and purified CCAX. The contact angle was increased from ∼ 21.3° to 67-74° after washing or bleaching CCAX. Acetylation of bleached CCAX showed the highest thermal resistance (325 °C), had low Tg (125°C) and a high contact angle (80°), and its films were stronger (strength ∼ 67 MPa; Young's modulus ∼ 2241 MPa) and more flexible (∼ 13%). These characteristics make purified CCAX a suitable material to be used as a matrix for film applications.