Effect of different hemicelluloses characteristics on film forming properties

• Alkaline extraction of hemicelluloses from agricultural waste was performed.
• Hemicelluloses physico-chemical properties for film elaboration were analyzed.
• Obtained alkaline hemicelluloses provided brownish films with lignin contamination.
• Alkaline hemicelluloses after delignification provided less colored films.
• Agricultural wastes suitability as hemicelluloses sources was demonstrated.

Hemicelluloses are known to have good gas barrier properties makes them of interest to film applications. Corn cob, cotton waste, olive, apple tree pruning, pepper and chilli wastes were used as hemicelluloses sources for films production. Hemicelluloses were recovered from these wastes by direct alkaline extraction and raw material delignification. The hemicelluloses and their films were characterized using different analytical techniques (IR-ATR, TGA, DSC, HPLC, nitrobenzene oxidation, GPC, 13C NMR, DMA). Hemicelluloses obtained by direct alkaline extraction produces brownish films (≤4.46% lignin, Mw = 30,997–91,796, Tg = 140–150 °C). The presence of lignin and Ara/Xyl enhanced the film forming properties. Delignified hemicelluloses produced less colored films (Mw = 17,449–20,180, Tg = 140–150 °C) and Ara/Xyl ratio improved film forming capacity although a possible cellulose contamination could be observed. This study demonstrated the suitability of different agricultural wastes for hemicelluloses recovery and their physico-chemical properties for first step film elaboration.