Sushanta K. Samal

Polypropylene—Bamboo/Glass Fiber Hybrid Composites: Fabrication and Analysis of Mechanical, Morphological, Thermal, and Dynamic Mechanical Behavior:

Hybrid composites of polypropylene reinforced with bamboo and glass fibers (BGRP) were fabricated using an intermeshing counter rotating twin screw extruder followed by injection molding. Maleic anhydride grafted polypropylene (MAPP) has been used as a coupling agent to improve the interfacial interaction between the fibers and matrix. The mechanical properties of the hybrid composites were studied from tensile, flexural, and impact tests. Mechanical tests indicated an increase in tensile, flexural, and impact strength of the BGRP hybrid composites at a bamboo:glass fiber ratio of 15:15 ratio in the presence of 2 wt% of MAPP. Nearly, 69, 86, and 83% increase in tensile flexural and impact strength respectively has been observed as compared with virgin PP. The fiber matrix interfacial morphology of the tensile fractured specimens was studied using scanning electron microscopy (SEM) which showed less fiber pullout and comparatively less gaps between the fiber and the base matrix in the case of MAPP treated hybrid composites. The crystallization, melting behavior and thermal stability of the hybrid composites were investigated employing differential scanning electron microscopy (DSC) and thermogravimetric analysis (TGA). Thermogravimetric analysis (TGA) showed an increase in thermal stability of the matrix polymer with incorporation of bamboo and glass fibers, confirming the effect of hybridization and efficient fiber matrix interfacial adhesion. The dynamic mechanical analysis (DMA) showed an increase in storage modulus (E′) indicating higher stiffness in case of hybrid composites as compared with untreated composites and virgin matrix. The tan δ spectra presented a strong influence of fiber content and coupling agent on the α and γ relaxation process of PP.

Polypropylene Nanocomposites: Effect of Organo-modified Layered Silicates on Mechanical, Thermal & Morphological Performance

The present article reports the mechanical, thermal and morphological characteristics of polypropylene — maleic anhydride grafted polypropylene —organically modified MMT (PP-PP-g-MAH-OMMT) nanocomposites. PP nanocomposites were prepared by melt mixing in a twin screw extruder followed by injection moulding. Sodium montmorillonite has been organically modified using quaternary ammonium intercalants. A comparative account with commercial quaternary ammonium modified clay; Cloisite 15A has also been presented. Mechanical tests showed considerable improvement in tensile, flexural and impact properties of PP matrix with the incorporation of organically modified nanoclays. Furthermore, the quaternary ammonium intercalants exhibited improved performance with an optimum improvement in compatibilized PP/Cloisite 15A nanocomposites. The morphology of the nanocomposites has been examined using wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM). Morphological findings revealed efficient dispersion of organically modified nanoclays within the PP matrix. PP-g-MAH compatibilized PP/Cloisite 15A nanocomposites displayed finely dispersed exfoliated nanomorphology as compared with other systems. The crystallization, melting behavior and thermal stability of the nanocomposites has been studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) which indicated an increase in crystallization temperature as well as thermal stability of PP matrix in Cloisite 15A nanocomposites. DMA curves also confirmed an increase in storage modulus of PP matrix in the nanocomposites, indicating an increase in the stiffness of the matrix polymer with the addition of organically modified nanoclays.

Banana/Glass Fiber-Reinforced Polypropylene Hybrid Composites: Fabrication and Performance Evaluation

Hybrid composites of Polypropylene (PP) reinforced with intimately mixed short banana and glass fibers were fabricated using Haake twin screw extruder followed by compression molding with and without the presence maleic anhydride grafted polypropylene (MAPP) as a coupling agent. Incorporation of both the fibers into PP matrix resulted in an increase in tensile, flexural and impact strength with an increasing level of fiber content upto 30 wt% at banana: glass fiber ratio of 15:15 wt% and 2 wt% of MAPP. The rate of water absorption for the hybrid composites decreased due to the presence of glass fiber and coupling agent. The effect of fiber loading in presence of coupling agent on the dynamic mechanical properties has also been analyzed to investigate the interfacial properties. An increase in the storage modulus (E′) of the treated composite indicates higher stiffness. The tan δ spectra confirms a strong influence of fiber contents and coupling agent on the α and β relaxation processes of PP. The nature of fiber matrix adhesion was examined through scanning electron microscopy (SEM) of the tensile fractured specimen. Thermal measurements were carried out employing differential scanning calorimetry (DSC) and the thermogravimetric analysis (TGA) which indicated a decrease in the crystallization temperature and thermal stability of PP with the incorporation of MAPP treated banana and Glass fiber.

Effect of Clay Types on the Mechanical, Dynamic Mechanical and Morphological Properties of Polypropylene Nanocomposites

In the present investigation Polypropylene–Maleic anhydride grafted polypropylene–organically modified MMT (PP-MAPP-OMMT) nanocomposites were prepared by melt mixing in a twin screw extruder followed by injection molding. The effect of clay chemistry and compatibilizer on the properties of the nanocomposites has been studied. Sodium montmorillonite has been organically modified using quaternary and alkyl amine intercalants. A comparative account with commercial quaternary ammonium modified clays i.e Cloisite 20A, Cloisite 15A and Cloisite 30B has been presented. Storage modulus of PP matrix also increased in the nanocomposites, indicating an increase in the stiffness of the matrix polymer with the addition of organically modified nanoclays. The morphology of the nanocomposites has been examined using wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM). Morphological findings revealed efficient dispersion of organically modified nanoclays within the PP matrix. MAPP compatibilized PP/Cloisite 15A nanocomposites displayed finely dispersed exfoliated nanomorphology as compared with other systems.

Hybridization Effect of Glass Fibre on Mechanical, Morphological and Thermal Properties of Polypropylene-Bamboo/Glass Fibre Hybrid Composites

Polypropylene/bamboo fibre-reinforced composites (BFRP) and polypropylene-bamboo/glass fibre based hybrid composites (BGRP) using an intermeshing counter-rotating twin-screw extruder followed by injection moulding in which maleic anhydride grafted polypropylene (MAPP) was used as a compatibilizer. The effect of hybridization on the mechanical performance of hybrid composites has been assessed. It was observed that replacement of 15 wt.% of bamboo fibre by 15 wt.% of glass fibre with 2 wt.% of MAPP on a total amount of 30 wt.% of fibre content showed optimum mechanical performance. The water uptake of the hybrid composites was also found to be less than that of their unhybridized counterpart. The crystallization, melting behaviour and thermal stability of the hybrid composites were investigated employing differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). TGA thermograms showed an increase in thermal stability of the matrix polymer after incorporation of bamboo and glass fibres, confirming the effect of hybridization and efficient fibre matrix interfacial adhesion. The fibre-matrix interfacial morphology of the tensile fractured specimens was studied using scanning electron microscopy (SEM) which showed less fibre pullout and fewer gaps between the fibre and the base matrix in case of MAPP-treated hybrid composites.

Recent Development of Biobased Epoxy Resins: A Review

ABSTRACT Currently, the utilization of renewable resources for sustainable technology is in the renown of consumer as well as industrial attention, especially, chemical industries because of their availability, low cost, credentials toward environmental issues such as lower ecotoxicity, CO2 footprints, and inbuilt biodegradability. These natural properties are being taken advantage of in research and development, with vegetable oil-, furan-, lignin-, rosin-,vanillin-, and itaconic acid-derived biobased epoxy resin being used in various applications including paints, coatings, adhesives, and biomedicine. The present review mainly focuses on the utilization of natural resources for the synthesis of biobased epoxy and its curing agents. GRAPHICAL ABSTRACT

Thermal, Morphological and Dynamic Mechanical Characterization of Melt Blended PC Nanocomposites

Polycarbonate (PC) nanocomposites were prepared by melt intercalation technique in an intermeshing co-rotating twin-screw extruder. Both unmodified (Na+MMT) and organo-modified (Cloisite 10A & OMMT) clays were used for the preparation of nanocomposites. The effect of addition of clays on the morphological and dynamic mechanical properties of PC matrix has been studied. The wide angle X-ray (WAXD) studies reveal a dominated exfoliated morphology of the nanocomposites at a clay content of 5%. The intercalated morphology is predominated upto clay content of 3%. Transmission electron microscopy (TEM) demonstrated the co-existance of intercalated/exfoliated morphology in all the composites. Dynamic mechanical analysis (DMA) shows an increase in storage modulus indicating higher stiffness in case of organomodified clay filled composites as compared to unmodified & virgin matrix.

Fabrication and Characterization of Polypropylene/Ethylene-Octene Copolymer Blend Nanocomposites

PP/EOC thermoplastic blend nanocomposites were prepared by melt intercalation technique using an intermeshing co-rotating twin screw extruder. The organoclay (Na+ MMT, Cloisite 20A, Cloisite 30B) content was varied between 0-5wt. % whereas the blend composition was kept constant (70PP: 30EOC) as optimized in our previous work. The effects of clays on the mechanical and rheological properties have been studied. Mechanical studies of PP/EOC nanocomposites reveal a significant increase in the impact strength upto a clay content of 3%. X-ray diffraction (XRD) analysis showed a significant increase in the interlayer gallery space with increase in clay loading. The rheological characterization made employing parallel plate rheometer revealed a maximum increase in storage modulus (G’) and loss modulus (G”) in case of modified clay indicating higher stiffness of the nanocomposites as compared to unmodified nanocomposites. Time Temperature superposition (TTS) was employed to generate various viscoelastic mastercurves.

Crystallization of Polymer Blend Nanocomposites

Abstract The concept of reinforcing nanofiller into multicomponent polymer blend has been successfully developed for commercial aspects. The addition of a nanofiller to the polymeric blend resulted in lightweight, stronger, and cheaper structures, which are the main goals of recent materials science and engineering applications. The crystallization behavior of the polymer blends was significantly affected by the compatibilization action and nucleation effect delivered by the nanofiller reinforcement. Nanoparticles can either increase or decrease the crystallization rate of a semicrystalline polymer. Besides the influence on nucleation, a retarding effect of nanofiller on the crystal growth of polymer matrices has been a point of consideration. This chapter highlights several types of polymeric blends in combination with various nanofillers.

Bio-based tri-functional epoxy resin (TEIA) blend cured with anhydride (MHHPA) based cross-linker: Thermal, mechanical and morphological characterization

ABSTRACT A novel renewable resource based tri-functional epoxy resin from itaconic acid (TEIA) was blended with petroleum based epoxy resin (DGEBA) and fabricated at different ratios. Then, it was by thermally cured with methylhexahydrophthalic anhydride (MHHPA) in presence of 2-methylimidazole (2-MI) catalyst. The tensile, modulus, strength of virgin epoxy resin (41.97 MPa, 2222 MPa) increased to 47.59 MPa, 2515 MPa, respectively, with the addition of 30% of TEIA. The fracture toughness parameter, critical stress intensity factor (KIC) revealed enhancement of toughness in the TEIA bio-based blends system. The thermomechanical properties of TEIA (tri-functional epoxy resin from itaconic acid) modified petroleum-epoxy networks were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The fracture morphology was also studied by the scanning electron microscopy and atomic force microscopy respectively.