Effect of alkali treatment on jute fibre composites

Abstract

The aim of our project was the improvement of the mechanical properties of natural-fibrereinforced composites, as a result of optimization of the properties of jute fibres by the use of an NaOH treatment process. Jute fibres were subjected to a 5% alkali (NaOH) solution treatment for 0, 2, 4, 6 and 8 h at 30°C. The composites reinforced with alkali treated fibres showed improved mechanical properties. The improvement was maximum for the composites prepared with 4 h treated fibres. The ILSS improved by 26.56% and Bending Strength by 27.53%. An improvement in the crystallinity in the jute fibres increased its tenacity by 12%, 68% and 79% after 4, 6 and 8 h of treatment respectively. The rate of change of flexural strength and modulus were found to be linear with wt% of alkali treated fibres and the %breaking strain was reduced by 28% for composites prepared using 8-hr treated jute fibre. On plotting the different values of slopes obtained from the rates of improvement of the flexural strength and tenacity, against the NaOH treatment time, two different failure modes were apparent before and after 4 h of treatment. In the first region between 0 and 4 h, fibre pull out was predominant whereas in the second region between 6 and 8 h, transverse fracture occurred with a minimum fibre pull out. This observation was well supported by the SEM investigations of the fracture surfaces.