Studies on Composite Filaments from Nanoclay Reinforced Polypropylene

Joshi, Mangala,Shaw, M.,Butola, B.S. The Korean Fiber Society 2004 Fibers and polymers Vol.5 No.1

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.

Comparative Study of P-aramid Based Soft and Stiff Composite Panels for Protective Application

Rupayan Roy,Abhijit Majumdar,Bhupendra Singh Butola 한국섬유공학회 2019 Fibers and polymers Vol.20 No.2

In this research work, the authors investigated the impact behaviour of Kevlar based flexible and stiff composites. These composites were prepared by using natural rubber latex (NR) and epoxy resin respectively as matrix and p-aramid (Kevlar 129) fabric as reinforcement. For flexible composites, the ratio of reinforcement and matrix was 90:10, and for stiff composites, the ratio was 40:60. In both the cases, two layers of Kevlar fabric were used. Stitched fabric panels consisting of two layers of Kevlar were used as control. It was observed that the flexible composites exhibited 2.8 times higher puncture force whereas for stiff composites the value was 6.6 times in comparison to only stitched panels. In terms of impact energy absorption, flexible composites showed 73 % higher value as compared to the stitched panels whereas for stiff composites, 86 % reduction was witnessed.

Leveraging the Antibacterial Properties of Knitted Fabrics by Admixture of Polyester-Silver Nanocomposite Fibres

Prakash Khude,Abhijit Majumdar,Bhupendra Singh Butola 한국섬유공학회 2018 Fibers and polymers Vol.19 No.7

Leveraging the antibacterial properties of polyester-cotton knitted fabrics has been attempted in this research by admixture of small proportion of polyester-silver nanocomposite fibres. Polyester-cotton (50:50) yarns were spun by mixing 10, 20 and 30 % (wt.%) polyester-silver nanocomposite fibres with normal polyester fibres so that overall proportion of polyester fibre becomes 50 %. The proportion of cotton fibre was constant (50 %) in all the yarns. Three parameters, namely blend proportion (wt.%) of nanocomposite fibres, yarn count and knitting machine gauge were varied, each at three levels, for producing 27 knitted fabrics. Polyester-cotton knitted fabrics prepared from polyester-silver nanocomposite fibres showed equally good antibacterial activity (65-99 %) against both S. aureus and E. coli bacteria. Antibacterial properties were enhanced with the increase in the proportion of polyester-silver nanocomposite fibres, yarn coarseness and increased compactness of knitted fabrics. Yarn count and blend proportion of nanocomposite fibre were found to have very dominant influence in determining the antibacterial properties of knitted fabrics.

Multi-objective Optimisation of Antibacterial Activity and Comfort of Knitted Fabrics Made from Polyester-Silver Nanocomposite Fibres

Prakash Khude,Abhijit Majumdar,Bhupendra Singh Butola,Rajib Bhattacharyya 한국섬유공학회 2023 Fibers and polymers Vol.24 No.9

Textile materials have long been recognised as media supporting the growth of microorganisms. For various applications including sports apparel, textile materials should have an optimum level of antibacterial activity without deteriorating the clothing comfort. This study deals with the multi-objective optimisation of antibacterial activity and comfort of knitted fabrics made from polyester-silver nanocomposite fibres using the desirability function approach. Comfort properties such as air permeability and moisture vapour transmission along with antibacterial activity have been considered to determine the ‘overall desirability’. Blend proportion of the polyester-silver nanocomposite fibre (%), yarn count (Ne), knitting machine gauge (inch-1) and type of fabric (100% polyester or polyester-cotton blend) have been considered as the four independent variables. The optimum desirability was found to be 0.64 which is acceptable. To validate the results of optimisation, a new fabric sample was prepared with the optimum combination of input parameters. The validation sample showed good agreement with the optimised values of antibacterial activity and comfort properties.

Determination of Macronutrients, Micronutrients and Heavy Metals Present in Spilanthes acmella Hutch and Dalz: Possible Health Effects

Salam Bhopen Singh,Kamal Singh,Sandeep Singh Butola,Suraj Rawat,Kusum Arunachalam 한국생약학회 2020 Natural Product Sciences Vol.26 No.1

The study was conducted for quantitive determination of macronutrients, micronutrients and heavy metals present in Spilanthes acmella Hutch and Dalz, a traditionally used important medicinal plant. The results illustrated the presence of substantial amounts of essential nutrient elements in different parts of the plant. K and Mg were detected in the range between 36.35 ± 1.01 to 67.78 ± 1.33 g/kg and 2.17 ± 0.13 to 7.02 ± 0.84 g/kg of DWS respectively. While the essential micronutrients Fe, Na, Mn, Zn and Cu were detected in the range between 62.62 ± 12.72 to 856.95 ± 76.61 mg/kg, 365.47 ± 23.84 to 633.03 ± 38.12 mg/kg, 51.66 ± 7.77 to 186.33 ± 13.92 mg/kg, 41.87 ± 2.85 to 53.89 ± 3.79 mg/kg and 18.49 ± 2.07 to 48.71 ± 4.89 mg/kg of DWS respectively. Besides, heavy metals (Cd, Ni and Pb) detected in some of the plant samples were beyond the maximum permissible limit (MPL) of FAO/WHO for herbal medicines. The concentrations of the essential nutrient elements except zinc were significantly different in different parts of the plant (p < 0.001). Further variation in the concentrations of the elements in the plant was observed with respect to seasonal changes and geographical conditions. Nevertheless the findings corroborate ethnomedicinal significance of the plant and signify the possibilibity of utilizing its standardized products for preparation of food supplements as well as multidimensional therapeutic herbal medicines.

Tailoring the Rheology of Shear Thickening Fluids by Regulating the Particle Size of Dispersed Phase for Enhancing the Impact Resistance of Aramid Fabrics

Komal Talreja,Aranya Ghosh,Sanchi Arora,Abhijit Majumdar,Bhupendra Singh Butola 한국섬유공학회 2022 Fibers and polymers Vol.23 No.5

Rheological behaviour of shear thickening fluid (STF) is influenced by particle size, particle shape, concentrationof particles etc. This study deals with the effect of particle size and its distribution on the rheological behaviour of STFs andensuing impact resistance of Kevlar® fabrics treated with them. Synthesis of submicron sized silica particles of three differentsizes was carried out by following the Stöber method. Corresponding STFs consisting of 67 % silica particles were preparedand their rheological behaviour was evaluated. Decrease in particle size coupled with particle size uniformity significantlycontributes to enhancement in dilatancy of STFs. Further, Kevlar® fabric was impregnated with these STFs for assessing theirimpact resistance performance. Fabric impregnated with STF prepared from the finest and uniform silica particles, having thehighest peak viscosity, exhibited the best impact resistance performance among all STF impregnated fabrics. These findingsshow that the particle size and its distribution decisively influence the thickening behaviour of STF which in turn plays acritical role in determining the impact energy absorption by high-performance fabrics.

Prediction of rheology of shear thickening fluids using phenomenological and artificial neural network models

Sanchi Arora,Animesh Laha,Abhijit Majumdar,Bhupendra Singh Butola 한국유변학회 2017 Korea-Australia rheology journal Vol.29 No.3

Prediction models for the viscosity curve of a shear thickening fluid (STF) over a wide range of shear rate at different temperatures were developed using phenomenological and artificial neural network (ANN) models. STF containing 65% (w/w) silica nanoparticles was prepared using polyethylene glycol (PEG) as dispersion medium, and tested for rheological behavior at different temperatures. The experimental data set was divided into training data and testing data for the model development and validation, respectively. For both the models, the viscosity of STF was estimated for all the zones with good fit between experimental and predicted viscosity, for both training and testing data sets.