Development of natural fiber reinforced polymer composite

Abstract

Natural fiber reinforced polymer composite has gained paramount importance in the composite research field because of versatility and clivers;ned nature of application field and environmental concern Retted, Vvoolenized,rclted and bleached jute fibers were collected from Banglade~h Jute Research Institute. Retted, relted ami bleached' variety of woven jute mals were collected Irom the Bangladesh Jute Mills COTporation (BJMC). Fibers were cut into 5:!:lmrn length and the woven jute fabrics were cut 10350mmx300mm dimension and dried for 12 hours In an oven allooac. Jute fiber surface waS analyzed under scanning eledron microscope (SEM). Different morphology of the fiber surface was detected. Woolcnization treatment severely removed the fiber binding materials e,g. lignin, hemicellulose etc, and leached out some portion of fibrous body of jutc fiber. Bleaching treatment in tum removed the lignin in between the fibrous bundle of jute fiber. Composite specimens >{ were fabricated at room temperature with standard cold press molding and hand layup utilizing methyl ethyl ketone peroxide (MEKP) as initiator and ortho phthalic unsaturated polyeMer resin as matrix. Resin over flow was always allowed for best wetting of the fiber. Maximum of Zo-Z5-volume percent of fiber ean be incorporated with this fabricating regime, with current instrumentation facility. ne woven jute fabrics showed constant resin impregnation factor during composite fabrication. Water absorption property of chopped jute and woven jute composite wa:; analyzed by ASTM D 570. Water absorption characteristics varied accon:liug to the fiber trcatmcnt and reinforcement orientation. Density and void content of composites were also carried out. Mechanical characteriz.ations of these fabricated composites were done using Universal Testing Machine. ASTM D3039 test method was followed for ten"le test of composite spe~imen; ASTM D 790 test method wa, lollowed for flexural or three point bend test of composite. At higher (15 - 20) volume percentage of chopped jute fiber composite showed higher tensIle strength than the refercnee polymer but in case of transverse loading tbese cDmpositc strength just reached the reference value of the polymer. Woven jute fabric reinforced composite showed higher strength behavior in either case of tensilc and transverse loading. Fallurc profile and failure surfaces were observed undcr a scanning electron • nuc[()scope (SEM) to view the post failure characteristics of the compo,ile body. Predominanl mode of failure for individual loadmg condition of these composilcs were analyzed comparing the failure profile. Effect of volume fraction of these composi(e~ on failure mode was also analyzed. Chopped jute composite showed interface and fiber (>Tienlalian dependence in both case of flexural and tensi1c loading with large number of fiber pullout. Woven jute laminates showed interface and fabric node (a 90. eros, point of yams wllhin woven fabric) dependence with fiber pullout for tensile loadmg. When the composites were loaded transversely shearing was a predominant mode of failure along with the interface and fabric node dep~mJcncc with severe fiber bridging anJ pullout. These mechanisms helped the laminates to sustain highcr load than that of the reference polymer at volume pcrcentagc lowcr than that of the chopped jute composite. Comparison of the SEM micrographs to analyze inlerface of the fracturc surface was carried out Differenl types of int~rfaee were observed, which are Hupposed to have direct relationship with the fiber lreatment procedure and mechanical properties of the jute fiber rcinforced composite. Maximum polymel'ic residue was observed on the woolenized fiber and minimum was seen on the reUedjute, in both case of chopped jule and woven jute remforeed composile. meached j ule e"ntained moderate amount of polymeric residue in either case of chopped jute and woven jute reinforced composile. AnalySIs of density, void percentage and strength of composile specimen were also carried out. Higher density and lower voiJ percentage was observed along with higher strength for chopped jule composite, Woven jutc fabric laminates showed no density and void conlcnt depcndence on lhe strength of compo;ite; anJ its strcngth is primarily governed witb the strcngtb of tbe yam. Composile powders were analY7-ed by Fourier Transformalion Infra Rcd (FTIR) spcctrometry to evaluate fiber-matrix interfacial bonding nature or compatibility of the fiber and the matrix. The spcctral data of composites were compared wilh lhe reference FTIR spectra of jute and cured polymer and it was found that the carbonyl (- CO) environment of jute and the carboxyl (COO-) environment of cured polyester had been changed in the composite. But these te~ts do not infer about good fiber matrix chemical mteraction and mechanical compatibility. Spectral data was compared with tcnsile and flcxural " - • strength to study the impact of interfacial bonding on the mechanical: properties of • composites.