Effects of corona discharge and UV treatment on the properties of jute-fibre epoxy composites

In this paper, tossa jute fibres were corona discharge and ultraviolet (UV) treated to improve the mechanical properties of natural-fibre/epoxy compos ites. Corona-treated fibres exhibited significantly higher polar components of the free surface energy with increasing treatment energy output. Owing to the difficulties in effective treatment of three-dimensional objects wit h corona discharge, the increase of polarity of treated yarns is relatively small, in comparison to the results achieved with single fibres. Furthermo re a decrease in the yam tenacity was observed with increasing corona energ y level. The UV treatment of the single fibres and yarns led to significant ly higher gains in polarity in comparison with those observed in relation t o corona-treated materials. Increasing treatment time at a constant bulb-sa mple distance or alternatively decreasing the distance significantly increa sed the polarity and decreased yam tenacity. To improve the overall mechani cal properties of jute/epoxy composites, an appropriate balance needs to be achieved between increased polarity of fibre surface and the decrease of f ibre strength subsequent to excessive surface oxidation by corona discharge or UV radiation. At the optimum treatment conditions an increase in the co mposite flexural strength of about 30% was achieved. (C) 2000 Elsevier Scie nce Ltd. All rights reserved.