Accumulation of industrial waste is a serious environmental problem, which lead to air and water pollution. Addition of industrial waste in polymer composites as reinforcement can enhance the various properties. To overcome this issue, an attempt has been made to investigate mechanical, tribological and water absorption behaviour of industrial waste (red mud) based sisal/glass fiber reinforced hybrid composites and also no research has been done on this. In this work, prepared the composite specimens using sisal fiber (35, 30, 25 and 20 wt%), red mud (0, 5, 10 and 15 wt%) through hand layup technique. In addition to this, glass fiber (5 wt%) and polyester matrix (60 wt%) are kept as constant. From the results, it is observed that, enhanced mechanical properties, minimum wear behaviour and good water resistance were observed on 30 wt% of sisal fiber and 5 wt% of red mud filled composite and recommending this material for marine applications due to good water resistance in sea water. Morphological analysis shows fiber breakages, voids, wear debris, minor cracks, voids and delamination.

The aim of this work is to study the effect of chitosan on mechanical and thermal properties of aloe vera fiber reinforced composites. In this work, we have fabricated the five different composites namely pure polyester composite (SP), pure aloe vera fiber composite (S0), 1 wt.% of chitosan filled aloe vera fiber composite (S1), 3 wt.% of chitosan filled aloe vera fiber composite (S3), and 5 wt.% of chitosan filled aloe vera fiber composite (S5) through simple hand layup method and investigated the mechanical and thermal properties. From the results, it is concluded that, 3 wt.% of chitosan filled aloe vera fiber reinforced composite was performed well in all the testing and it is suitable for various engineering applications such as automobile, aeronautical and marine. SEM analysis shows good adhesion behavior between fiber and matrix with the addition of chitosan. Further, 3 wt.% of chitosan can be added in natural fiber based polymer composites to enhance mechanical properties of the composites.