Mechanical properties of jute fibers and interface strength with an epoxy resin

Four different forms of jute fibers, namely untreated jute filament (UJF), sliver jute filament (SJF), bleached jute filament (BJF), and mercerized ju te filament (MJF), have been subjected to tensile strength analysis followi ng Weibull's theory. The MJF and BJF were obtained by the chemical modifica tion of the UJF. A minimum of 50 fibers of each type, at three different ga uge lengths, i.e., 15, 30, and 50 mm, were used to study the strength distr ibution and the effect of gauge length. The mean fiber strength was found t o be the maximum for UJF followed, in the order, by BJF, MJF, and SJF (simi lar to 700, similar to 660, similar to 580, and similar to 540 MPa, respect ively, at 50-mm gauge length). The strength was also found to decrease with an increase in gauge length. In all cases, good agreement was found with W eibull's statistical model. Single fiber composite tests, with an epoxy res in as the matrix, were carried out determine the critical fragment lengths and interfacial strength, following the Kelly-Tyson approach. The BJF was f ound to have the maximum interfacial adhesion (tau approximate to 140 MPa) followed by UJF, SJF, and MJF having tau values of similar to 83, similar t o 57, and similar to 47 MPa, respectively. Scanning electron microscope pic tures showed the fiber surface was physically modified by the various treat ments. (C) 2000 John Wiley & Sons, Inc.