Coconut fibre is obtained from the

Coconut fibre is obtained from the husk of the fruit of the coconut palm; the trees can grow up to 20 m, making harvesting a difficult job. People climb the tree to pick the nuts, or a pole with an attached knife is used. The fruits are dehusked with on a spike and after resetting, the fibres are subtracted from the husk with eating and washing. The fibres are strong, light and easily withstand heat and salt water. After nine months of growth, the nuts are still green and contain white fibre, which can be used for the production of yarn, rope and fishing nets. After twelve months of growth, the fibres are brown and can be used for brushes and mattresses. The combined use of coconut and sisal short fibres seem to delayed restrained plastic shrinkage controlling crack development at early ages. Many aspects of the use of coir fibres as reinforcement in polymer–matrix composites are described in the literature. Coir is an abundant, versatile, renewable, cheap, and biodegradable lignocellulosic fibre used for making a wide variety of products. Coir has also been tested as a filler or a reinforcement in different composite materials. Furthermore, it represents an additional agro-industrial non food feedstock (agro industrial and food industry waste) that should be considered as feedstock for the formulation of ecocompatible composite materials. Coconut coir is the most interesting products as it has the lowest thermal conductivity and bulk density. The addition of coconut coir reduced the thermal conductivity of the compositespecimens and yielded a lightweight product. Development of composite materials for buildings using natural fibre as coconut coir with low thermal conductivity is an interesting alternative which would solve environment and energy concern. Geethamma et al. have studied the dynamic mechanical behavior of natural rubber and its composites reinforced with short coir fibres. Coir fibre–polyester composites were tested as helmets, as roofing and postboxes. These composites, with coir loading ranging from 9 to 15 wt%, have a flexural strength of about 38 MPa. Coir–polyester composites with untreated and treated coir fibres, and with fibre loading of 17 wt%, were tested in tension, flexure and notched Izod impact. The results obtained with the untreated fibres show clear signs of the presence of a weak interface long pulled-out fibres without any resin adhered to the fibres—and low mechanical properties were obtained. Although showing better mechanical performance, the composites with treated fibres present, however, only a moderate increase on the values of the mechanical properties analyzed. Alkali treatment is also reported for coir fibres. Treated fibre–polyester composites, with volume fraction ranging from 10% to 30%, show better properties than composites with untreated fibres, but the flexural strength of these composites was consistently lower than that of the bare matrix. A maximum value of 42.3MPa is reported against a value of 48.5MPa for the neat polyester. Acetylation of coir fibres increases the hydrophobic behaviour, increases the resistance to fungi attack and also increases the tensile strength of coir– polyester composites. However, the fibre loading has to be fairly high, 45 wt% or even higher, to attain a significant reinforcing effect when the composite is tested in tension. Moreover, even with high coir fibre loading fractions, there is no improvement in the flexural strength. From these results, it is apparent that the fibre treatments reported so far did not significantly change the mechanical performance of coir–polyester composites. Although there are several reports in the literature which discuss the mechanical behaviour of natural fibres reinforced polymer composites. However, very limited work has been done on effect of fibre length on mechanical behaviour of coir fibre reinforced epoxy composites. Against this background, the present research work has been undertaken, with an objective to explore the potential of coir fibre as a reinforcing material in polymer composites and to
investigate its effect on the mechanical behaviour of the resulting composites. The present work thus aims to develop this new class of natural fibre based polymer composites with different fibre lengths and to analyse their mechanical behaviour by experimentation.