Electron beam effect on the tensile properties and topology of jute fibers and the interfacial strength of jute-PLA green composites

Abstract

Green composites that, in general, consist of cellulosebased natural fibers and polymer resins have many advantages like environmentally friendliness, light weight, costeffectiveness, biodegradability and acceptable mechanical properties over conventional glass fiber-reinforced polymer composites. However, natural fibers of hydrophilic character may cause weak interfacial adhesion with a polymeric resin of hydrophobic character, leading to reduction of the properties and performances of resulting green composites. Due to lack of interfacial adhesion between raw natural fibers and polymers, there have been many papers reporting the modification of fiber surfaces and the effect on the interfacial properties of green composites. In order to modify natural fiber surfaces and consequently to enhance the interfacial bonding to a polymer, chemical methods like alkalization and silane coupling and physical methods like electron beam irradiation and plasma treatment are frequently used. Electron beam technique has often been utilized for surface modification and property improvement of polymer materials like fibers, films, plastics and composites for the last decades. It may remove surface impurities and alter surface chemical characteristics at an appropriate irradiation condition. Electron beam processing is a dry, clean and cold method with advantages such as energy-saving, high throughput rate, uniform irradiation and environmental safety. Poly(lactic acid), referred to as PLA, is obtainable from natural resources, thermoplastic and completely biodegradable. As it combines with natural fibers like jute, kenaf, etc., the material would be not only highly reinforced but also ecobenign and biodegradable. The objective of the present work is to explore the effect of jute fiber surface modification on the interfacial shear strength of jute-PLA green composites. The paper deals with the change of single fiber tensile property, fiber surface topology, and chemical composition occurring in jute fibers irradiated at different dosages of electron beam, discussing on their effect on the interfacial adhesion between jute fibers and PLA.