H. Md. Akil

The Effect of HVA-2 Addition on the Properties of PP–EPDM–NR Ternary Blends

The effect of N, N′-m-phenylenebismaleimide (HVA-2) addition on the properties of polypropylene (PP)–ethylene–propylene diene terpolymer (EPDM)–natural rubber (NR) ternary blends is investigated in this study. The blends have been prepared in a laboratory internal mixer at 180 C and a rotor speed of 50 rpm. Process development, mechanical properties, and thermal and morphological studies are carried out for both PP–EPDM–NR blends with and without HVA-2. Results indicate that the torque values, the stabilization torque, tensile strength, and tensile modulus increased with the addition of HVA-2 in the blends, whereas elongation at break showed an opposite trend. The addition of HVA-2 reveals a tendency for the percentage of crystallinity (X c) to increase, but no significant evidence is observed in the thermogravimetric analysis. Scanning electron microscopy studies indicate that the formation of crosslinks in the rubber phases is responsible for the properties enhancement of PP–EPDM–NR blends with HVA-2.

Predicting the Coefficient of Thermal Expansion of Pultruded Composites with a Natural-Fiber Reinforcement

Thermal expansion problems for unidirectional pultruded composite samples were studied. The composite materials were subjected to temperatures ranging from 0 to 200°C in order to simulate service conditions. A thermal-mechanical analyzer was employed for gathering experimental data, and the results were compared with those generated using the ANSYS software and micromechanical models. A finite-element analysis (FEA) by utilizing ANSYS was also carried out. The thermal behavior of pultruded jute-fiber-reinforced unsaturated polyester composites was simulated, and the results obtained were then compared with experimental data and predictions provided by several micromechanical models. It is found that the Schapery and Chamis micromechanical models are more efficient in predicting the value of CTE in the longitudinal and transverse directions, respectively.

X‐Ray Powder Diffraction (XRD) Studies on Kenaf Dust Filled Chitosan Bio‐composites

Kenaf dust filled chitosan bio‐composites with various compositions of kenaf dust (i.e. 7%, 14%, 21% and 28%) were prepared using solution casting technique. The degree of relative crystallinity of the bio‐composites was determined using XRD method. Two distinguishable crystalline peaks were observed in the 2θ range of 5 to 40 ° which indexed as 020 and 110 respectively. It was noted that the maximum peak of intensity at 020 crystalline peak increased with addition of kenaf dust as well as the second maximum peak of intensity at 110. Consequently, Fourier Transform Infrared (FTIR) analysis was done to investigate the interaction between kenaf dust and chitosan matrix. From FTIR analysis, corresponding peak of chitosan was detected at wavelength of 3233.2 cm−1 indicated that there exist intermolecular interactions between kenaf dust and chitosan matrix. These results highlighted that there are greater intermolecular forces formed in chitosan with addition of kenaf dust. Intermolecular forces were attribute...

The Effect of Dicumyl Peroxide Vulcanization on the Properties & Morphology of Polypropylene/Ethylene-Propylene Diene Terpolymer/Natural Rubber Blends

ABSTRACT This article discusses some properties such as tensile properties, chemical and oil resistance, gel content, crystallinity, and morphology of polypropylene (PP)/ethylene-propylene diene terpolymer (EPDM)/natural rubber (NR) blends. Dicumyl peroxide (DCP) was applied as a crosslinking agent. In terms of tensile properties, peroxide vulcanized blend shows higher tensile strength and tensile modulus (stress at 100% elongation, M100) as compared with the unvulcanized blend. The elongation at break of the peroxide vulcanized blend is higher for the blend with NR rich content compared with the EPDM rich content. The improvements in chemical and oil resistance as well as gel content of peroxide vulcanized blends have also proved the formation of crosslinks in the rubber phase. Scanning electron microscopy (SEM) micrographs from the surface extraction of the blends support that the crosslinks have occurred during dynamic vulcanization. Dynamical vulcanization with DCP has decreased the percent crystallinity of blends that can be attributed to the formation of crosslinks in the rubber.

Flow Behavior of Polypropylene/Ethylene-Propylene Diene Terpolymer/Natural Rubber (PP/EPDM/NR) Blends by Torque Rheometer: The Effect of N,N-m-Phenylene Bismaleimide (HVA-2) Addition

Abstract Blends of polypropylene (PP)/ethylene-propylene diene terpolymer (EPDM)/natural rubber (NR) with different ratio were investigated using a Haake torque rheometer. The effect of N,N-m-phenylene bismaleimide (HVA-2) addition on the flow behavior of PP/EPDM/NR blends also was studied. The torque data was collected at different rotor speeds in the range of 30–60 rpm and different processing temperatures in the range of 170–190°C. The recorded data were interpreted in terms of apparent shear rate, apparent shear stress, and apparent viscosity. The shear stress–shear strain curve shows that all blends follow the power law where the pseudoplasticity behavior of melt viscosity increases with increasing NR content as well as addition of HVA-2. The apparent viscosity of the blends was found to increase with increasing NR content in the blend. The addition of HVA-2 increases the apparent viscosity due to the formation of cross-linking in rubber phase. However, blends with HVA-2 show lower flow activation energies than do similar blends without HVA-2. Scanning electron microscopy (SEM) shows good correlation with the flow properties of the blends.

The Effects of Dynamic Vulcanization by Dicumyl Peroxide (DCP) and N,N-m-Phenylene Bismaleimide (HVA-2) on the Properties of Polypropylene (PP)/Ethylene-Propylene Diene Terpolymer (EPDM)/Natural Rubber (NR) Blends

ABSTRACT This paper discusses some properties of the polypropylene (PP)/ethylene-propylene diene terpolymer (EPDM)/natural rubber (NR) blends, such as tensile properties, heat resistance, gel content, and morphology. Dicumyl peroxide (DCP) and N,N-m-phenylene bismaleimide (HVA-2) and their combination were applied in PP/EPDM/NR blends as cross-link agents. In terms of tensile properties, the combination of DCP with HVA-2 shows the highest tensile strength and elongation at break in all PP/EPDM/NR blend ratios compared to similar blends, except with DCP or HVA-2 alone. The addition of HVA-2 produced blends with good heat resistance, while the combination of DCP with HVA-2 shows the highest gel content dealing with the cross-links formation. SEM micrographs from the surfaces extraction of the blends support that the cross-links have occurred during dynamic vulcanization process.

Tribological Characteristics of Green Biocomposites

Owning to the environmental concerns and sustainable development, green biocomposites are increasingly explored and developed to replace conventional composites. Polymer composites used in tribological application have received great attention from researchers due to its self-lubricating properties, versatile fabrication process, low in cost and easy to tailor their properties with wide range of functional fillers. The past research in using green biodegradable materials reinforced polymers in tribological study has established a good understanding on tribological behaviour of natural fibre-reinforced polymer composites (NFRPCs). In this chapter, the tribological performance of various natural fibres reinforced polymer composites reported in the literature is reviewed. Furthermore, the effect of different important factors of natural fibre on wear and friction of polymers is discussed. Most of the polymer materials showing certain degree of enhancement in tribological properties after reinforced with natural fibre. Further optimization of its performance is possible by selecting optimum fibre loading, fibre length, fibre treatment, sliding orientation and combining with other fillers to form hybrid system composites. Finally, based on our current understanding, we have speculated some future trends and directions of NFRPCs in the field of tribology.

Production of hybrid inorganic/carbon nanotube fillers via chemical vapor deposition for advanced polymer nanocomposites

Abstract Carbon nanotubes (CNTs) have been studied in the past decade for an array of applications due to their unique and versatile properties such as their mechanical, thermal, and electrical behavior. In the field of composites, they have shown a great promise to improve the properties of composites, such as thermal and electrical. This chapter deals with the synthesis and characterization of CNT hybrid fillers for polymer nanocomposite materials. Synthesis of CNTs concentrates on the chemical vapor deposition technique. The synthesized hybrid fillers are further characterized by field emission scanning electron microscope, high-resolution transmission electron microscope, Raman spectroscopy, and X-ray diffraction. In addition, the optimized synthesis parameters are also presented and discussed. Finally, comparative studies were conducted between chemically hybrid-filled and physically hybrid-filled polymer nanocomposites in terms of their typical applications.