R. Somashekar

Characterization of castor oil-based interpenetrating polymer networks of PU/PS

A series of interpenetrating polymer networks (IPNs) of polyurethane/polystyrene (PU/PS; 90/10, 75/25, 60/40, and 50/50) have been synthesized by condensation reaction of castor oil with methylene diisocyanate and styrene, employing benzoyl peroxide as initiator. Polystyrene is extracted from IPNs by the Soxhlet extraction method. The IPNs of PU/PS before and after PS extraction were characterized for physical, optical, and X-ray diffraction properties

Differential scanning calorimetry and wide‐angle X‐ray scattering studies of bread staling

Wide angle X-ray scattering (WAXS) was used to follow the development of crystal size and strain during the staling of bread containing different additives. In this it was observed that one can classify the good anti-staling additives as gelatin, propylene glycol, maltodextrin and anti-staling enzyme corresponding to the order of increasing crystal size for a particular Bragg reflection in all the samples and correlate using DSC (differential scanning calorimetry) studies of all the bread compositions containing different additives.

Photocatalytic treatment of municipal wastewater using modified neodymium doped TiO2 hybrid nanoparticles.

Photocatalytic degradation of municipal wastewater was investigated using reagent grade TiO2 and modified neodymium doped TiO2 hybrid nanoparticles. For the first time, surface modification of Nd3 + doped TiO2 hybrid nanoparticles were carried out with n-butylamine as surface modifier under mild hydrothermal conditions. The modified nanoparticles obtained were characterized by Powder XRD, FTIR, DLS, TEM, BET surface area, zeta potential and UV-Vis Spectroscopy. The characterization results indicated better morphology, particle size distribution and low agglomeration of the nanoparticles synthesized. It was found that photodegradation of wastewater using surface modified neodymium doped TiO2 nanoparticles was more compared to pure TiO2, which can be attributed to the doping and modification with n-butylamine.

Structure–property relation in low-density polyethylene–starch immiscible blends

The effect of starch content, on the physico-mechanical properties viz., density, tensile strength and percentage elongation and optical properties like percentage transmittance at different wavelengths of low-density polyethylene/starch blended films has been investigated. The changes have been interpreted quantitatively in terms of microcrystalline parameters compiled using wide angle X-ray scattering data.

Structure-property relation in varieties of acid dye processed silk fibers

The changes in microstructural parameters in varieties of acid dye processed (Bombyx mori and Antheraea) silk fibers have been studied using wide angle X-ray scattering (WAXS) method. The crystal imperfection parameters like crystal size 〈N〉, lattice strain (g) and enthalpy (α*) have been determined by profile analysis using Fourier method of Warren. These results were crosschecked with the one obtained by matching the simulated intensity profile obtained from one-dimensional Hosemanns paracrystalline model. In all this computation, we have used (201) reflection observed in these silk fibers. We have also computed volume-weighted and surface-weighted crystal sizes and compared the changes in these parameters with the measured physical properties like tensile strength and percentage of elongation at break in these fibers.

Synthesis and characterization of castor oil based polyurethane-polyacrylonitrile interpenetrating polymer networks

A series of interpenetrating polymer networks (IPNs) of castor oil based polyurethane/polyacrylonitrile (PU/PAN: 80/20, 60/40, 50/50, 40/60 and 20/80) were synthesized by condensation reaction of castor oil with methylene diisocyanate and acrylonitrile, employing benzoyl peroxide (BPO) and ethylene glycol dimethylacrylate (EGDM) as initiator and crosslinkers respectively. The physical, chemical, optical and some of the mechanical properties of PU/PAN were studied. Phase stabilization in IPNs was investigated by wide angle X-ray (WAXS) profile analysis. Variation of crystal size distribution was studied in these polymer networks.

Crystal structure of raw pure Mysore silk fibre based on (Ala-Gly)2-Ser-Gly peptide sequence using Linked-Atom-Least-Squares method

We have carried out crystal structure analysis of raw pure Mysore silk fibers belonging toBombyx mori on the basis of model parameters of Marshet al using Linked-Atom-Least-Squares technique. The intensity of all the reflections were computed employing CCP13 software. We observe that the molecular modification is essentially same as β-pleated structure with antipolar-antiparallel arrangements formed by hydrogen bonds. The essential differences observed in the structure are highlighted and discussed

WAXS studies on silk fibres treated with acid (blue) and metal complex (brown) dyes

The changes in microstructural parameters in bivoltine and multivoltine silk fibres due to (i) degumming, (ii) bleaching, (iii) blue acid dye and (iv) brown metal complex dye processing have been studied using wide angle X-ray scattering (WAXS) method. The crystal size has been determined by Fourier analysis and also by matching the simulated intensity profile obtained from one-dimensional Hosemanns paracrystalline model using (201) reflection observed in these silk fibres. Volume weighted and surface weighted crystal sizes have been estimated and compared. The variations of tenacity and elongation results justify the results of X-ray studies reported here.

Effect of physical and chemical modifications on microcrystalline parameters of silk fibers

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