Thermomechanical and dynamic mechanical properties of bamboo/woven kenaf mat reinforced epoxy hybrid composites

Abstract

The dimensional stability and dynamic mechanical properties on bamboo (non woven mat)/kenaf (woven mat) hybrid composites was carried out in this study. The hybridization effect of bamboo (B) and kenaf (K) fibers at different weight ratio were studied at B:K:70:30, and B:K:30:70 while maintaining total fiber loading of 40% by weight. The coefficient of thermal expansion (CTE) and dynamic mechanical properties of composites were analyzed by thermomechanical anlayzer (TMA), and dynamic mechanical analyzer (DMA), respectively. Positive hybridization effects were observed on B:K:50:50 hybrid composite with lowest CTE and highest dynamic mechanical properties among all composites. The dimensional stability were strongly influence by the fiber orientation where all composites shows prominent expansion in the transverse fibers direction but relatively low expansion in longitudinal fibers direction. Dynamic mechanical properties in term of complex modulus (E*), storage modulus (E′), loss modulus (E″), Tan delta and Cole-Cole plot were studied. DMA results reveal that B:K:50:50 hybrid composite possess the highest complex modulus due to the strong fiber/matrix interfacial bonding which supported by the coefficient of effectiveness and Cole-Cole plot. Hence, it is concluded that 50:50 weight ratio of bamboo and kenaf fibers is the optimum mixing ratio to enhance both dimensional and dynamic mechanical properties of hybrid composites, and it can be utilized for automotive or building materials applications which demand high dimensional stability and dynamic mechanical properties.

The Effect of Bi-Functionalized MMT on Morphology, Thermal Stability, Dynamic Mechanical, and Tensile Properties of Epoxy/Organoclay Nanocomposites

“…The storage modulus (E ), loss modulus (E"), and tan delta curves of the pristine epoxy and epoxy nanocomposites are shown in Figure 12, and the obtained DMA parameters data are summarized in Tables 6 and 7. The ability of the material to store or return energy is represented by E and provides valuable insight on the load bearing capacity [46], stiffness [23], degree of crosslinking [47], and fiber/matrix interfacial bonding [48]. The E decreases as the temperature increases with a steep change in modulus was observed in the temperature range of 60-90 • C. This can be denoted as the glass transition (T g ) region or α relaxation of the polymer whereby it represents the movement of the polymer main chain.…”

“…The effects of the bi-functionalized MMT on the morphological, thermal stability, dynamic, mechanical, and tensile properties of the epoxy/OMMT nanocomposites were studied. As part of our previous work [22][23][24], the data obtained from this work can be utilized to produce a high-performance natural fiber/nanoclay/epoxy hybrid nanocomposite which could potentially be used for automotive or building and construction applications.…”

Static and dynamic mechanical analysis of geometrically different kenaf/PLA green composite laminates

“…Loss modulus is an indirect indication of interfacial strength of a composite. If a composite is having high loss modulus value, it means more energy is required to split the fiber and matrix interface, which in turn will generate more heat at the interface . The loss modulus results of different kenaf/PLA composite laminates with respect to temperature are shown in Figure .…”

“…As shown in figure, initially loss modulus was constant due to absence of mobility of polymer molecules. Further, as the temperature got increased, the value of loss modulus also increased due to mobility of molecules …”

Surface Modification of Bamboo Fibers to Enhance the Interfacial Adhesion of Epoxy Resin-Based Composites Prepared by Resin Transfer Molding

“…After chemical modification of BFs, E' of modified BFs/EP composites was significantly increased, which can be ascribed to the superior toughness of BFs [16]. In the case of NaOH-modified BFs/EP composites, part of the hemicellulose and lignin were removed during hydrolysis; as a result, the relative content of cellulose in BFs increased while cellulose content could provide good mechanical strength [16,45]. In addition, surface-treated BFs could reduce the free volume and decrease polymer chain mobility due to the good interfacial interaction between the BFs and matrix.…”