Morphological, chemical, and thermal characteristics of chitosan nanocomposite films reinforced with steam-exploded microfibrillated cellulose

Abstract

The objective of the study was to investigate and analyze the morphological, chemical, and thermal properties of chitosan nanocomposite films reinforced with microfibrillated cellulose (MFC). MFC, which was isolated via steam explosion assited with alkaline treatment, produced a diameter size average of about 50 nm with self-aggregated ball-like shapes. Obtained chitosan/MFC nanocomposite films had a varied thickness average and moisture content in the range from 3.70 to 13.34%. Chitosan films had a good UV prevention without sacrificing transparency nature. The reinforcement of MFC 0.5–2.5% and MFC 5–10% in the films induced irreversible self-aggregation with a size average of about 0.5 and 10 µm, respectively. Carbon and oxygen elementals varied whereas nitrogen slightly decreased along with MFC incorporation. The addition of MFC into chitosan films noticeably shifted FT-IR wavenumber and intensity because of chemical interaction between chitosan and MFC functional groups. MFC enhanced the thermal stabilities of chitosan films due to high remnant weight of the films after thermal decomposition although MFC accelerated the decomposition and degradation of the films. The inclusion of MFC into chitosan polymer did not show anti-bacterial properties against Escherichia coli due to no clear zone of inhibition and no zone of inhibition indices around the tested films.