Characterization and properties of organo-montmorillonite modified lignocellulosic fibers and their interaction mechanisms

In this study, lignocellulosic natural fibers (NFs), namely, cellulose fiber/flour (CF) and lignin flour (LF) separated from poplar wood flour (WF) as well as xylan as a representative of hemicellulose flour (HF), were modified with organo-montmorillonite (OMMT) through a two-step method. Some physical and mechanical properties of the thus-modified materials were investigated. Besides this, the interaction mechanisms between OMMT and these NFs were studied. The results showed that OMMT partly intercalated with HF and completely exfoliated in LF. However, it hardly penetrated into CF. Owing to that, OMMT reduced the moisture content of HF and LF and improved their mechanical properties. But for CF, OMMT showed negative/little effect on its physical/mechanical properties. No reaction was found between OMMT and CF. It mainly reacted with the amorphous constituents of the NFs by basically forming links with the carboxyl/phenolic hydroxyl end groups of the HF/LF molecular chains.