Influence of chemical modification on hemp–starch concrete

Abstract

As a result of growing environmental consciousness, the issues of sustainability and industrial ecology are guiding the development of the next generation of materials and processes. Renewable resources such as hemp hurds in the field of green polymeric materials with their new range of applications represent an important basis in order to fulfil the ecological objective of creating eco-friendly materials.This work deals with the impact of several chemical treatments of hemp hurds on the properties of hemp–starch composite which is made of 100% of natural resources. Two compositions were manufactured, the first one with untreated hemp hurds in starch matrix and the second one with treated hemp hurds in starch matrix. A set of chemical treatments was performed to solubilize hemicelluloses and lignin seal surrounding the cellulose bundle in the first step and then a coupling agent was used to provide a stable bond between hemp hurds and starch matrix. The influence of the treatments on hemp hurds characteristics was investigated by scanning electron microscopy (SEM), differential thermal analysis (DTA), thermogravimetric analysis (TGA) and attenuated total reflectance spectroscopy (ATR). Moreover, the mechanical properties of green composites were studied and it seems that alkaline treatment followed by silane treatment improves the stiffness of composites according to the results of mechanical properties after treatments.