SEM observations of the fractured surfaces of coir composites

Coir composites had been prepared using coir fiber (both continuous and short fiber) as reinforcement with both thermosetting and thermoplastics as matrices. The composite specimens were prepared using both untreated and chemically modified such as defatted, PMMA grafted, PAN grafted and cyanoethylated coir fibers. Coir-polyester and glass/coir-polyester hybrid composites were prepared by modified hand-lay-up technique whereas coir-BAK composites were prepared by film-stacking method and coir-PP composites were prepared by compression molding technique. The specimens were subjected to tensile and impact tests and the fractured surfaces were observed under SEM. The SEM micrographs of the fractured surfaces of composites showed varied extents of fiber pull-outs under both failure modes. A good correlation between the SEM study and the mechanical strengths of the composites could be established. The improved mechanical strengths of chemically modified coir composites had been explained on the basis of SEM study.