» Figure 2 shows the influence of microfibrillar angle of the fibre on the work of fracture values of different natural fibre reinforced polymer composites. It can seen that microfibrillar angle in plant fibres plays an important role in determining the impact behavior of these composites and this effect should be taken into account along with the other parameters while predicting the impact properties of natural fibre composites

» Sisal fibre-low density polyethylene (LDPE) composites showed a better reinforcing effect due to the high matrix ductility and high strength/modulus ratio of sisal fibres as compared to that of LDPE matrix.

» The CTDIC (cardanol derivative of toluene diisocyanate) treatment reduced the hydrophilic nature of the sisal fibre and thereby enhanced the tensile properties of the sisal-LDPE composites. They found that peroxide treated composites showed an enhancement in tensile properties due to the peroxide induced grafting. It was also found that permanganate treated composites also showed a similar trend.

» The effects of various chemical treatments on the tensile properties of sisal-polyethylene composites are presented in Table 4. Treatments using chemicals such as sodium hydroxide, isocyanate, permanganate and peroxide were carried out to improve the bonding at the fibre-polymer interface.