Essential Work of Fracture and Acoustic Emission Study on TPNR Composites Reinforced by Kenaf Fiber

Abstract

Kenaf fiber (KF) based thermoplastic natural rubber (TPNR) composite was produced by melt blending with polypropylene (PP). Kenaf fiber (15% by volume) and TPNR were mixed in as Haake 600p internal mixer. The fracture behavior of the TPNR matrix and of TPNR-kenaf (with and without maleic anhydride grafted polypropylene, MAPP) composites was evaluated using the essential work of fracture (EWF) method and double edge notched tensile (DENT) specimens. Various ligament lengths were employed ranging from 4 to 12 mm. The strain rate was fixed at 2 mm/min. The specific work of fracture (w e ) and plastic work (bw p ) showed the highest energy for TPNR that corresponds to its ductility and allows the application of the EWF approach. It was found that the presence of kenaf fibers and MAPP reduced the toughness of TPNR and changed the ductile fracture to brittle behavior. SEM observation revealed that energy absorption mechanisms include matrix deformation, fiber pullout, and fiber breakage. Acoustic emission (AE) was employed to analyze the failure processes further. The signals emitted by composites were substantially higher than that of the TPNR matrix, reflecting that also the failure mechanisms were affected by the fibers incorporated.KEY WORDS: thermoplastic natural rubber, kenaf fiber, essential work of fracture, acoustic emission.

Benefits of low kenaf loading in biobased composites of poly(L‐lactide) and kenaf fiber

“…Kenaf (Hibiscus cannabinus, L.; family Malvaceae) is a tropicalseason herbaceous annual plant, related to cotton, okra, and hibiscus that can be produced across a large range of cultural conditions and locations, and has excellent potential as a commercial crop for industrial applications. [7][8][9] It is grown widely for cordage in Asia. Products from kenaf have many uses that include animal litter, a fiberglass substitute, animal forage, cellulose fiber, potting mix, pulp and paper making, sacs, canvasses, and carpets.…”

Caracterização morfológica de nanocristais de celulose por microscopia de força atômica

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