Reactive blending of thermoplastic starch and polyethylene-graft-maleic anhydride with chitosan as compatibilizer

• Main Authors: Kittisak Jantanasakulwong, Noppol Leksawasdi, Phisit Seesuriyachan, Somchai Wongsuriyasak, Charin Techapun, Toshiaki Ougizawa
• Format: Journal
• Published: 2018
• Subjects: Chemistry; Materials Science
• Online Access: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84979567354&origin=inward; http://cmuir.cmu.ac.th/jspui/handle/6653943832/55431
• Institution: Chiang Mai University

© 2016 Elsevier Ltd Cassava starch was melt-blended with glycerol (70/30 wt%/wt%) at 140 °C to prepare thermoplastic starch (TPS). Chitosan (CTS) was premixed with starch and glycerol, in acidified water (lactic acid 2 wt%), at 1, 5 and 10 wt%/wt%. TPS/CTS was then melt-blended (160 °C) with polyethylene-graft-maleic anhydride (PE-MAH). Phase determination and scanning electron microscopy indicated TPS/PE-MAH/CTS had a co-continuous morphology and CTS-induced phase inversion to give dispersed PE-MAH particles in a TPS matrix. Tensile strength at break and elongation, melt viscosity, fracture toughness and water contact angle of TPS/PE-MAH were improved by CTS incorporation. TPS/PE-MAH/CTS blends decreased the melting temperature of TPS and PE-MAH compared to the neat polymers. FTIR confirmed a reaction had occurred between amino groups ([Formula presented]2) of CTS and the MAH groups of PE-MAH. This reaction and the enhanced miscibility between TPS and CTS improved the mechanical properties of the TPS/PE-MAH/CTS blend, particularly at 5 wt%/wt% CTS.