The effect of chemical treatment of hemp hurds slices in three solutions (EDTA (Ethylenediaminetetraacetic acid), NaOH and Ca(OH)₂) on the properties of natural material was discussed in this paper. Changes in the morphology, chemical composition and structure as well as thermal stability of hemp hurds before and after their modification were investigated by using FTIR (Fourier transform infrared spectroscopy), XRD (X-ray powder diffraction analysis) and TG (thermogravimetry)/DSC (differential scanning calorimetry). Size exclusion chromatography (SEC) measurements were used for determination of degree of cellulose polymerization of hemp hurd samples. Chemical modification is related to the partial removal of non-cellulosic components of lignin, hemicellulose and pectin as well as waxes from the surface of hemp hurd slices. Another effect of the chemical treatment applied is connected with increasing the crystallinity index of cellulose determined by FTIR and XRD methods. Decrease in degree of cellulose polymerization and polydispersity index in chemically modified hemp hurds compared to the original sample was observed. Increase in thermal stability of treated hemp hurd was found. The most significant changes were observed in alkaline treated hemp hurds by NaOH.

Lightweight lignocellulosic composites are potentially contributing to sustainable development. However, lignocellulosic fillers are not always fully compatible with an inorganic matrix, which causes a variety of adverse outcomes such as the coherence and mechanical properties of composites. Therefore, experiments are made with natural fiber surface treatment. Experiments were conducted to further development of natural fibers - hemp shives of another application to lightweight composites. Untreated and chemically treated hemp shives surfaces by NaOH, Ca(OH)2 and EDTA were characterized by FTIR and TG. Changes in the FTIR spectra at 1730, 1625 and cm-1 indicated that hemicellulose and lignin from natural fiber surfaces were removed by alkaline treatment. Thermal stability of hemp shives was studied using thermal gravimetric and DSC method

This paper deals with preparation of lightweight composites based on hemp hurds and alternative binders. Impact of hemp hurds properties (mean particle length) on the behavior of composites (mechanical and physical properties) based on alternative binders (hydrated lime without and with cement; zeolite, MgO-cement) is studied. The results show that the most suitable binder is MgO– cement. Hemp nature as well as mean particle size of hemp hurds slices influences the behavior of composites

In this paper, water sorption behavior of 28 days hardened composites based on hemp hurds and inorganic binder was studied. Two kinds of absorption tests on dried cube specimens in deionized water bath at laboratory temperature were performed. Short-term (after one hour water immersion) and long-term (up to 180 days) water absorption tests were carried out to study their durability. Short-term water sorption behavior of original hemp hurds composites depends on mean particle length of hemp and on binder nature. The comparative study of long-term water sorption behavior of composites reinforced with original and chemically modified hemp hurds in three reagents confirmed that surface treatment of filler influences sorption process. Based on evaluation of sorption curves using a model for composites based on natural fibers, diffusion of water molecules in composite reinforced with original and chemically modified hemp hurds is anomalous in terms of the Fickian behavior. The most significant decrease in hydrophility of hemp hurds was found in case of hemp hurds modified by NaOH and it relates to change in the chemical composition of hemp hurds, especially to a decrease in average degree of cellulose polymerization as well as hemicellulose content.