Showing papers by "Muhammad Remanul Islam published in 2018"

Characterization of polyamide 6.10 composites incorporated with microcrystalline cellulose fiber: Effects of fiber loading and impact modifier

Abstract: Microcrystalline cellulose (MCC) fiber‐reinforced polyamide 6.10 (PA) composites were prepared in the presence of an impact modifier (IM), exxelor VA1803 (VA), by melt compounding process. Fiber loading was considered from 20 to 30 wt.%, whereas IM was varied from 2.0 to 5.0 wt.%. Composites were characterized by tensile test, impact test, dynamic thermal mechanical analysis (DTMA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and X‐ray diffraction (XRD). Composites’ fractured surfaces were examined by scanning electron microscope (SEM). In addition, fiber size distribution was also analyzed. Result analyses showed that the fiber incorporation changed the tensile strength (TS) slightly, but the tensile modulus (TM) significantly. The TM was found to be improved by 45% at the amount of fiber loading of 30 wt.%. Moreover, the thermomechanical properties revealed that the storage modulus (SM) and loss modulus (LM) were increased due to the incorporation of MCC, which was improved further by the uses of 5.0 wt.% of VA. The MCC possess high crystallinity index and high crystallite size along with enhanced mechanical and thermal properties. Therefore, the extraordinary benefit of using MCC in PA was evaluated in terms of thermomechanical, structural, and thermal properties in the presence of the impact modifier.

Dispersion characteristics of hydroxyl and carboxyl-functionalized multi-walled carbon nanotubes in polyester nanocomposites

Abstract: Multi-walled carbon nanotube (MWCNT) reinforced polyester-based composites were prepared by mixed blending in a solvent. Orthophthalic unsaturated polyester was blended individually with different types of non-functionalized and functionalized MWCNTs. Two types of functional groups: hydroxyl (-OH) and carboxyl (-COOH) were introduced with MWCNTs for the nanocomposites. The mechanical properties of the composites, like tensile, three-point bending and impact energy were evaluated. Fourier transform infrared spectroscopy was used for the functional group analysis. The dispersion characteristics of the samples were observed by transmission electron microscopy and field-emission electron microscopy. In addition, the thermal decomposition and melting behavior of the samples was assessed by differential scanning calorimetry and thermogravimetric analysis. The properties were varied due to the variation of the functional groups. The result analysis showed that the entangled agglomerations of hydroxyl-functionalized MWCNTs were destroyed to relatively smaller clusters. The hydroxyl-functionalized MWCNTs were more effective for homogeneous dispersion and contributed for better mechanical properties of the composites, compared to non-functionalized and carboxyl group-functionalized MWCNTs.

Mechanical, interfacial, and fracture characteristics of poly (lactic acid) and Moringa oleifera fiber composites

Abstract: Three different processing techniques, extrusion, injection, and compression, were followed to fabricate poly (lactic acid) (PLA) and Moringa oleifera fiber (MOF) based composites. Chopped fibers of length 3–5 mm were used for the extrusion followed by injection molding, whereas long-length fibers (~100 mm) were used for compression molding process. For compression molding, long-length fibers were spread in single and double layers. The interfacial shear strength of the composites was evaluated by fiber pull-out testing. Composites were characterized for fracture behavior and mechanical properties. Additionally, surface morphology was also observed by scanning electron microscopy, whereas crystalline properties were evaluated by X-ray diffraction analysis. Analyses revealed that compression molding with double layers of long-length fibers reinforcement showed better properties than other samples. Tensile strengths of extruded and compression processed samples (double-layered) were 75.5 and 81.1 MPa, which are approximately 33% and 44% higher respectively than neat PLA (56.5 MPa). The crack generation of PLA during applied load was observed and found eliminated for the double-layered sample processed via compression molding. It was found that compression molding with double layer can be considered as easy and less time-consuming method for composite preparation, with nearly 8 wt.% of less fiber consumption compared with extrusion/injection molding.