Mechanical properties of thermally treated hemp fibers in inert atmosphere for potential composite reinforcement
- 1 August 2003
- journal article
- Published by Taylor & Francis in Materials Research Innovations
- Vol. 7 (4), 231-238
- https://doi.org/10.1007/s10019-003-0258-y
Abstract
Hemp (Cannabis Sativ L.) is an important lignocellulosic raw material for the manufacture of cost-effective environmentally friendly composite materials. From an earlier study it was found that when hemp bast fibers were heated above the glass transition temperature of lignin, there was a migration of lignin to the surface of the fiber. The preliminary observations showed that heat treatment in inert environment seemed to provide enough fiber opening without affecting the associated tissues of the fibers. Here, hemp fibers were given heat treatment in an enclosed vessel in air as well as inert environment and their mechanical properties were compared to the raw hemp fiber. It was found that there were openings of fibers upon heating, both along the length as well as along the diameter or the width directions. For the same weight of the fiber, the total count of fibers increased during heat treatment, with increment up to 32% for inert environment and 39% for air environment; the increment was mainly due to opening up of fibers into lesser diameters than the original fibers. The strength properties were strongly influenced by the diameter of the fibers, with the lesser fibers contributing to greater tensile strength and modulus. The overall tensile strength and modulus of fibers treated in inert environment were found to have increased, probably due to production of fibers of lesser diameters, presumably with less number of natural defects. The overall strength of fiber treated in air environment, however, decreased even though there was opening up of fibers in this case as well. This was due to oxidation of various constituents of fiber which contributes strength.This publication has 17 references indexed in Scilit:
- Analysis of the flax fibres tensile behaviour and analysis of the tensile stiffness increaseComposites Part A: Applied Science and Manufacturing, 2002
- CHEMISTRY AND DELIGNIFICATION KINETICS OF CANADIAN INDUSTRIAL HEMPJournal of Wood Chemistry and Technology, 2001
- Influence of fiber length on the mechanical properties of wood-fiber/polypropylene prepreg sheetsMaterials Research Innovations, 2001
- Environmental Durability of Flax Fibres and their Composites based on Polypropylene MatrixApplied Composite Materials, 2000
- Steam explosion of flax — a superior technique for upgrading fibre valueBiomass and Bioenergy, 1998
- Synthesis and polymerization of lignin‐based macromonomers. III. Radical copolymerization of lignin‐based macromonomers with methyl methacrylateJournal of Applied Polymer Science, 1993
- Complexity in the spatial localization and length distribution of plant cell‐wall matrix polysaccharidesJournal of Microscopy, 1992
- Wettability of kraft pulps-effect of surface composition and oxygen plasma treatmentJournal of Adhesion Science and Technology, 1992
- The nature of adhesion in composites of modified cellulose fibers and polypropyleneJournal of Applied Polymer Science, 1991
- On the deformation and setting of the wood cell wallEuropean Journal of Wood and Wood Products, 1966