Mangala Joshi

Polymeric Nanocomposites—Polyhedral Oligomeric Silsesquioxanes (POSS) as Hybrid Nanofiller

Abstract Polyhedral oligomeric silsesquioxane (POSS), a hybrid nanostructured macromer has been used in the last decade for preparation of polymeric nanocomposites. Its versatile chemistry, which lends it for almost infinite chemical modification, sets it apart from other nanostructured fillers like nanoclays, carbon nanotubes, and carbon nanofibers. Depending on its functionality, 3‐D network, bead or pendant type‐POSS based polymeric nanocomposites can be synthesized. These have the potential to be designed for products with specific nanostructures for specific end‐use applications. This article discusses the trends in current research involving use of POSS macromers for modification of mainly thermal and viscoelastic properties of various polymers.

A Review on Carbon Epoxy Nanocomposites

Carbon nanotubes are the major component of nanotechnology and a considerable area of research, due to their outstanding physical and mechanical properties. Since their discovery in 1991, extensive research has been carried out to understand and exploit these unique properties in the form of composites for various applications. But the main challenge lies in transferring the properties of carbon nanotubes to the nanocomposites successfully. In this paper, recent research in the field of carbon nanotubes reinforced epoxy composites and carbon epoxy three phase composites are reviewed.

Nanotechnology – a new route to high-performance functional textiles

The use of nanomaterials- and nanotechnology-based processes is growing at a tremendous rate in all fields of science and technology. Textile industry is also experiencing the benefits of nanotechnology in its diverse field of applications. Textile-based nanoproducts starting from nanocomposite fibers, nanofibers to intelligent high-performance polymeric nanocoatings are getting their way not only in high performance advanced applications but nanoparticles are also successfully being used in conventional textiles to impart new functionality and improved performance. Greater repeatability, reliability and robustness are the main advantages of nanotechnological advancements in textiles. Nanoparticle application during conventional textile processing techniques, such as finishing, coating and dyeing, enhances the product performance manifold and imparts hitherto unachieved functionality. New coating techniques like sol-gel, layer-by-layer, plasma polymerization etc. can develop multi-functionality, intelligence, excellent durability and weather resistance to fabrics. The present paper focuses on the development and potential applications of nanotechnology in developing multifunctional and smart nanocomposite fibers, nanofibers and other new finished and nanocoated textiles. The four main areas of textile chemical processing, namely nanofinishing, nanocoating, nanocomposite coating and nanodyeing, are covered in the first section of this paper and the second section deals with developments in nanocomposite fibers and nanofibers. The influence of nanomaterials in textile finishing and processing to enhance product performance is discussed. Nanocoating is a relatively new technique in the textile field and is currently under research and development. Polymeric nanocomposite coatings, where nanoparticles are dispersed in polymeric media and used for coating applications, are the most promising route to develop multifunctional and intelligent high-performance textiles. Not much research has been done on applying the concept of nanotechnology in dyeing of textiles except a few reports on dye particle size reduction, structural change in fibers or the surface etching of textiles to create nanostructured surfaces. The reduction in water consumption during nanotechnology applications in textile processing has the potential to control the effluent problems of a textile process house. The most researched area to produce multifunctional, smart fibers is the preparation of nanocomposite fibers where the exceptional properties of nanoparticles have been utilized to enhance and impart several functionalities on conventional textile grade fibers. Nanofibers are gaining popularity in some specialized technical applications such as filter fabric, antibacterial patches and chemical protective suits. Nanotechnological advances in these two areas of nanocomposite fibers and nanofibrous forms have also been reviewed.

Polyesters and polyamides

Part 1 Polyester and polyamide fundamentals: Polyester resins Polyamide fibres Manufacture of polyester fibres Manufacture of polyamide fibres Poly (lactic acid) fibres (PLA) Environmental impact of polyester and polyamide textiles. Part 2 Improving functionality of polyesters and polyamides: Specialty fibres from polyester and polyamides Property enhancement through blending Weaving technology for manufacturing high performance fabrics Advances in coloration of polyester textiles Flame retardant polyester and polyamide textiles Advances in functional finishes for polyester and polyamide textiles The impact of nanotechnology on polyester and polyamides. Part 3 Applications of fibrous polyesters and polyamides: Polyester fibre-apparel applications Medical applications Sports applications Automotive applications Applications of polyesters and polyamides in civil engineering.

Studies on composite filaments from nanoclay reinforced polypropylene

The development of high tenacity, high modulus monofilaments from Polypropylene/Clay nanocomposite has been investigated. Pure sodium montmorillonite nanoclay was modified using hexadecyl trimethyl ammonium bromide (HTAB) via an ion exchange reaction. Pure and modified clay were characterized through X-ray diffraction, FTIR and TGA. The modified clay was melt blended with polypropylene (PP) in presence of a swelling agent. Composite filaments from PP/Clay nanocomposite were prepared at different weight percentages of nanoclay and the spinning and drawing conditions were optimized. The filaments were characterized for their mechanical, morphological and thermal properties. The composite PP filaments with modified clay showed improved tensile strength, modulus and reduced elongation at break. The composite filaments with unmodified clay did not show any improvement in tensile strength but the modulus improved. The sharp and narrow X-ray diffraction peaks of PP/nanoclay composite filaments indicate increase in crystallinity in presence of modified clay at small loadings (0.5%). The improved thermal stability was observed in filaments with modified as well as unmodified clays.

Studies on the thermal, dynamic mechanical and rheological behaviour of short-glass-fibre-reinforced composites based on poly(butylene terephthalate)/high density polyethylene blends

Abstract Blends of poly(butylene terephthalate) (PBT)/high density polyethylene (HDPE)/ionomer (IONO) polymers, at a blending ratio of 76/19/5 (by weight), were reinforced with short glass fibres (GFs) at levels of 10–30 wt% in order to enhance the mechanical properties for load-bearing engineering applications. The melting and crystallization behaviour of the composites, studied by differential scanning calorimetery (d.s.c.), indicate the presence of an increase in crystallinity in the presence of the glass fibres. Dynamic mechanical thermal analysis (d.m.t.a.) shows that the introduction of glass fibres reduces damping to a greater extent than would be expected theoretically. Incorporation of glass fibres increases the storage modulus, when compared to the unreinforced system, at all temperatures studied. The presence of short glass fibres increased the melt viscosity and decreased the extrudate swell, with the effect being more pronounced at higher temperatures. Rheological data have been analysed on the basis of fibre length (or aspect ratio) and/or distribution of the fibre lengths by using the rheological model proposed by Maron and Pierce.

Nanostructured coatings for super hydrophobic textiles

The promising aspects of nanocomposite coatings to mimic the nano roughened self cleaning surface of lotus leaf is explored in this paper. A detailed study on nanosilica and clay based nanocomposite coatings using dip coating and layer by layer self assembly (L–b–L) is being described where lotus leaf effect has been mimicked on the cotton fabric surface using these particles as they develop nanosized surface roughness which helps to produce a super-hydrophobic surface. Nanosilica performs better in creating nano roughness on cotton fabric wherein the contact angle is

Effect of Process Parameters on Layer-by-layer Self-assembly of Polyelectrolytes on Cotton Substrate

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SYNTHESIS AND CHARACTERIZATION OF CHITOSAN NANOPARTICLES WITH ENHANCED ANTIMICROBIAL ACTIVITY

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POSS/polypropylene hybrid nanocomposite monofilaments by reactive extrusion

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