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Jaipur, India

University of Rajasthan is a public and state university and one of the oldest university in the Indian state Rajasthan, located in the city Jaipur. It was set up on 8 January 1947 as the University of Rajputana and was given its current name in the year 1956. Wikipedia.

Chauhan N.P.S.,University of Rajasthan
Journal of Industrial and Engineering Chemistry | Year: 2013

Novel polyfunctional acetyl and hydroxyl bearing functional terpolymer (HQFCA) derived from 8-hydroxyquinoline (HQ), 4-chloroacetophenone (CA) and formaldehyde (F) has been synthesized by complex condensation polymerization in the presence of an acid catalyst. The structure and morphology of terpolymer were elucidated by FTIR-ATR, one-dimensional NMR (1H NMR, 13C NMR and DEPT-135 experiment), two-dimensional NMR (HSQC and TOCSY), pyrolysis GC-MS, gel permeation chromatography (GPC), nitrogen absorption, and optical microscopy (OM). Principal pyrolysis products generated from HQFCA units were 8-hydroxy-5,6-dimethylquinoline, 8-hydroxy-2-methylquinoline and 4-chloroacetophenone. This reactive terpolymer can be used as synthons for exchange membrane preparation and biomedical coating applications. © 2012 The Korean Society of Industrial and Engineering Chemistry. Source

A new monomer, (E)-4-acetylpyridine oxime (APO), was prepared by reaction of 4-acetylpyridine and hydroxylamine hydrochloride. Its terpolymers with 4-hydroxyacetophenone (HA)/4-hydroxybenzaldehyde (HB) and formaldehyde (F) were synthesized by using an acid catalyst in 1:1:5M proportions. The synthesized monomer (APO) and its terpolymers were identified by FT-IR and 1H NMR spectroscopic data. The apparent number average molecular weight and viscosities were determined by gel permeation chromatography and Ubbelohde viscometer, respectively. Thermal stability of these resins was determined by differential scanning calorimetry (DSC). The activation energy (Ea) values of the thermal decompsition were investigated with thermogravimetric analysis (TGA) by isoconversional Flynn-Wall-Ozawa method. Empirical kinetic models, as well as generalized master plots, were applied to explain the degradation mechanisms of terpolymers. The terpolymers strongly inhibited the growth of a wide variety of microorganisms, including Grampositive, Gram-negative bacteria and fungi. Copyright © 2013 Taylor & Francis. Source

A terpolymerpoly (vanillin-co-furfural-co-4-methylacetophenone) has been prepared by poly-condensation technique in the presence of an acid catalyst. The structure of terpolymer has been elucidated on the basis of various physico-chemical techniques like FT-IR, 1H NMR, Pyrolysis (Py) (gas chromatography/mass spectroscopy, GC/MS), nitrogen adsorption/desorp-tion analysis, gel permeation chromatography, thermogravimetry - derivative of thermogravi-metry (TG-DTG), and differential scanning calorimetry. The apparent activation energies (E a) of each step (0.1≤ α ≤0.9) during thermal degradation have been determined using Flynn-Wall-Ozawa method. The degradation through random scission and unzipping mechanism is discussed based on the kinetics by nonisothermal kinetics by TG-DTG and products obtained by Py (GC/MS). The type of solid-state mechanism is three-dimensional diffusion. © 2012 Taylor & Francis. Source

Chauhan N.P.S.,University of Rajasthan
Designed Monomers and Polymers | Year: 2014

A monomer, vanillin oxime (VO), has been synthesized from vanillin and hydroxylamine hydrochloride, and its terpolymer resin VO-formaldehyde-p- hydroxyacetophenone (VOFHA) has also been synthesized by condensation of VO, formaldehyde, and p-hydroxyacetophenone (HA) in 1:2:1 M proportion in the presence of hydrochloric acid. The structures of monomer and terpolymer have been investigated by FT-IR and 1H NMR techniques. The number-average molecular weight and polydispersity index of the terpolymer were found to be 5337.6 g/mol and 1.33, respectively, by gel permeation chromatography. Apparent activation energies of the thermal decomposition of the terpolymer were determined using the Flynn-Wall-Ozawa method. Terpolymer (VOFHA) has shown highest zone of inhibition as compare to other terpolymer and standard drugs. This novel bio-responsive antimicrobial terpolymer shows promise for use in the control of medical devices associated infections. © 2013 Taylor & Francis. Source

Chauhan N.P.S.,University of Rajasthan
Journal of Macromolecular Science, Part A: Pure and Applied Chemistry | Year: 2012

This paper demonstrates synthesis of a self-assembled resin system containing p-acetylpyridine oxime, formaldehyde and p-methoxyacetophenone moieties in main chain and thermally cross-linkable periphery oxime groups, and application as antimicrobial coating in biomedical applications. The post-polymerization conversion from oxime into iminium groups was observed by heating scan, with exothermic peaks being at 194 to 247°C. Various degradation models including the Flynn-Wall-Ozawa (F-W-O), Kissinger-Akahira- Sunose (K-A-S), Tang (T) and Friedman (F) methods were employed to check the thermal stability of self-assembly by computing apparent activation energy. It has also exhibited strong biocidal properties against gram-positive and gram-negative bacteria, and fungi until the macrochain retains some positive charge. The obtained results prove that the structure of links, which combine the hydrophobic pyridine rings with the hydrophilic iminium groups, is responsible for the high biocidal activity of the resin system. © 2012 Copyright Taylor and Francis Group, LLC. Source

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