Mechanical Properties of Chopped Randomly Oriented Epoxy - Luffa Fiber Reinforced Polymer Composite

Abstract

This paper presents the study of the tensile, compressive, flexural, impact energy and water absorption characteristics of the luffa fiber reinforced expoxy polymer composites. Luffa fiber reinforced epoxy resin matrix composites have been developed by hand lay-up technique with varying process parameters such as fiber condition (treated and untreated), chopped randomly oriented and different volume fraction (30%, 40% and 50%). Tensile strength varies from 9 MPa to 20 MPa, compressive strength varies from 75 MPa to 105 MPa, flexural strength varies from 15 MPa to 140 MPa and impact energy varies from 0.25 Joules to 1.45 Joules, as a function of fiber volume fraction. The optimum mechanical properties were obtained at 40% of fiber volume fraction of treated fiber composites. Fracture surface of the composite shows that pull out and de-bonding of fiber is occurred.

Recent Developments in Luffa Natural Fiber Composites: Review

“…Sodium Hydroxide (NaOH) [25,44,[49][50][51] Hydrogen Peroxide (H 2 O 2 ) [27,54,55,[65][66][67] Acetic Acid (CH 3 COOH) [27,54,55] Carbamide CO(NH 2 ) [55] Methacrylamide [60,69] Benzoyl Chloride Permanganate (KMnO 4 ) [51,75] Acetic Anhydride, and Acetone [65] Furfuryl Alcohol followed by oxidation (sodium chlorite + acetic acid) [50] CaCl 2 , H 2 SO 4 , and Na 2 HPO 4 [57] Hypochlorite (NaClO) [58] Ethanol, BTDA Dianhydrides [64] HCl [56] Chlorine Bleach [46,77] CalciumPhosphate and Calcium Carbonate [78] CaOH 2 and Silane [71] Thermo-mechanical treatment and thermo-hydromechanical treatment [79] Heat treatment [80] Sodium hydroxide (NaOH)/alkaline treatment evidenced its capability in improving luffa fibers' microstructure by changing its chemical composition as well as removing all impurities [49,[59][60][61][62][63]70]. Treating luffa fibers with 4% NaOH at 120 • C for 3 h revealed the highest fiber crystallinity index and, in addition, combined chemical treatments switched luffa from a mat into a filament structure [67].…”

“…However, researches have considered scanning electron microscopy most often for inspecting the fiber surface morphology, voids presence, fiber/matrix interaction, and so on. Few researches scanned pure luffa samples [55,67,69], while others involved the following matrices: epoxy [44,50,51,59,[61][62][63]89,91], polyester [60,66,96], polypropylene [68], vinyl ester [64], geopolymer [100], pre-gelatinized cassava starch [101]. SEM micrographs of untreated and treated fibers are shown in Figures 3 and 4; FESEM micrographs of treated luffa/epoxy are illustrated in Figure 5.…”

“…Hence, the weight of these samples is measured and compared with their initial weight in order to calculate the weight change ratio [123,124]. Water absorption property was tested for LNFCs with several matrices such as: epoxy [49,50,59,62,63], polyester [24,60,66,95], polypropylene [68], vinyl ester [64], polylactic acid [80], pre-gelatinized cassava starch [101], as well as pure luffa bundles [27,55]. Since luffa fibers are hydrophilic in nature, their addition into a matrix increased the overall water absorption of the NFC due to the existence of homocellulose and pectin.…”

“…Yet the water turned blurry, which indicated that the polymeric matrix was losing some of its components [60]. However, untreated LNFC exhibited around 14% higher water uptake, compared to treated LNFC, which indicated that the latter had a better compatibility with the matrix [59,63]. Additionally, void content and density of the material significantly affected its water absorption [24].…”

Deciphering the pathways for deployment of different architecture of chemically treated and untreated fibers in polymeric materials for performance enhancement

“…The randomly oriented reinforcements are seen to provide good interfacial adhesion which leads to good mechanical properties and the properties provided depends on the amount and dispersion of the reinforcement in the matrix of the composite. [49][50][51] Similarly, nowadays another type of reinforcement has been used by researchers which is honeycomb reinforcement which has been discussed in the next section.…”