Chemically Treated Hemp Shives as a Suitable Organic Filler for Lightweight Composites Preparing

Technical hemp (Cannabis sativa) is recently in the forefront in the manufacture of lightweight composites, where hemp shives acts as a filler. Many research projects have been devoted to the study of enhancement of the adhesion at the fibres–matrix (polymer or mineral) interface, using of various methods for modification of the surface fibres and matrix or by use of interfacial additives. Incompability of interface between fibres and matrix, the tendency to form aggregates during processing and poor resistance to moisture can be eliminated by physical/chemical treatments of fibers and/or matrix or the use of coupling agents. The influence of chemically treated hemp shives (NaOH, Ca(OH)2 and EDTA) on physical (density, thermal conductivity and water absorbability) properties and compressive strength of hardened fibrous composites based on MgO-cement as binder was investigated. The lightweight composites made with modified fibers confirm different physical and mechanical properties in dependence on the character of reagent used for chemical treatment of hemp shives.^p