Technological watch

Modified hemp fibers intended for fiber?reinforced polymer composites used in structural applications—A review. I. Methods of modification

Natural fiber composites have experienced a renaissance in the last two decades as a response to societal demands for developing eco?friendly, biodegradable and recyclable materials. They are now being extensively used in everyday products as well as in automotive, packaging, sports and construction industries. Hemp fiber is being used in most of these products because of its superior mechanical properties. Like other natural fibers, hemp fibers require modifications in order to improve their properties and interfacial bonding with polymer matrices, and to reduce their hydrophilic character. These modification methods can be grouped into three major categories: chemical, physical and biological. Chemical methods use chemical reagents to reduce fibers' hydrophilic tendency and thus improve compatibility with the matrix. They also expose more reactive groups on the fiber surface to facilitate efficient coupling with the matrix. Physical methods change structural and surface properties of the fiber and thereby influence the interfacial bonding with matrices, without extensively changing the chemical composition of the fibers. They are cleaner and simpler than the chemical methods. Biological methods use biological agents like fungi, enzymes and bacteria to modify the fiber surface properties. These methods are not toxic like chemical methods and are not energy?intensive like physical methods. This paper presents an overview of recent developments in these methods. It is concluded that these methods almost invariably result in improvement in fiber/matrix interfacial bonding, resulting in increase in mechanical properties of the composites.

Publication date: 10/08/2019

Author: Fulga Tanas?, M?d?lina Z?noag?, Carmen?Alice Teac?, M?rioara Nechifor, Asim Shahzad

Reference: doi:10.1002/pc.25354

Polymer Composites


This project has received funding from the Bio Based Industries Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme under grant agreement No 837761.