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Zaidi M.G.H.,Govind Ballabh Pant University of Agriculture & Technology | Thakur A.,Govind Ballabh Pant University of Agriculture & Technology | Agarwal T.,Govind Ballabh Pant University of Agriculture & Technology | Alam S.,Defense Materials Stores Research Development and Establishment
Iranian Polymer Journal (English Edition) | Year: 2014

Synthesis and processing of polymer-based materials through green friendly methods involving supercritical fluids particularly supercritical carbon dioxide (SCC) has recently received substantial technological importance because of the commercial and industrial benefits involved. In the present work, a SCC assisted green and sustainable process has been developed to synthesize polypyrrole/polythiophene copolymers (PPCs). The process of synthesis has been conducted through ferric chloride-initiated chemical oxidative polymerization in the presence of various molar proportions of pyrrole to thiophene 0:1.0, 1.0:0, 1.0:1.0 and 1.0:2.0 at temperature ranging from 50 to 90 °C, 1,200 psi over 12 h in SCC. Polymerization below 90 °C afforded PPCs in semi-solid products, whereas polymerizations conducted at 90 °C under identical conditions have afforded the end products in complete solid state. The structure and properties of PPCs have been evaluated through ultraviolet-visible absorption and Fourier transform infrared spectra, elemental analysis, atomic force microscopy, simultaneous thermogravimetric-differential thermal analysis-differential thermogravimetry and four-point probe electrical conductivity methods. With molar proportion of thiophene, time and temperature, all the polymerization reactions have been conducted to completion resulting in PPCs with enhanced polymerization yield, rheoviscosity, dispersion of polypyrrole into polythiophene matrix and thermal stability. This has contributed a simultaneous loss in the electrical conductivity of PPCs. © 2014 Iran Polymer and Petrochemical Institute. Source


Agrawal V.,Govind Ballabh Pant University of Agriculture & Technology | Vishnoi S.,Govind Ballabh Pant University of Agriculture & Technology | Zaidi M.G.H.,Govind Ballabh Pant University of Agriculture & Technology | Alam S.,Defense Materials Stores Research Development and Establishment | Rai A.K.,Allahabad University
International Journal of Polymer Analysis and Characterization | Year: 2010

[60] Fullerene (C60) almost completely inhibits the polymerization of most vinyl monomers, but our investigation shows that the concentration of radical initiators and reaction conditions greatly enhances conjugation formation. In the present investigation, a series of [60] fullerene-polymethyl methacrylate conjugates was synthesized through 2,2-azobisisobutyronitrile (AIBN)-initiated in situ polymerization of methyl methacrylate (MMA) under different reaction conditions in supercritical carbon dioxide (scCO2). This has afforded corresponding [60] fullerene-PMMA conjugates with [60] fullerene content (%) and rheoviscosity range of 0.79-4.69% and 1.069-1.345 Mpa s, respectively. The process of in situ polymerization was monitored at different concentrations (mol/dL) of AIBN (304.50-761.25 × 10-3) and MMA (9.41-23.53 × 10-3), and temperatures (60°-90°C), pressures (1400-2000 psi), and time (2-8 h). The progress of in situ polymerization was monitored rheoviscometrically in tetrahydrofuran at 25 ± 1°C. Selected [60] fullerene-PMMA conjugates were characterized through UV-vis, GPC, FT-IR, 1HMMR, 13CNMR spectra, and thermal characterization by TG. © Taylor & Francis Group, LLC. Source


Zaidi M.G.H.,k-Technology | Agarwal T.,k-Technology | Alam S.,Defense Materials Stores Research Development and Establishment | Rai A.K.,Allahabad University
Fullerenes Nanotubes and Carbon Nanostructures | Year: 2011

A synthetic route to prepare fullerene [60] polyvinyl pyridine composites (FPVPC) in supercritical carbon dioxide (scCO 2) is presented. The synthetic route involve 2, 2'-azobisisobutyronitrile (AIBN) initiated free radical polymerization of vinyl pyridine (VPY) in presence of fullerene [60] (C60) under various conditions in scCO 2. This has afforded FPVPC ranging yield (%): 8.08-72.79, C60 content (wt%): 1.35-7.25, and rheoviscosity: 0.20-0.75 (mPaS), respectively. The formation of FPVPC has been ascertained through Uv-vis, FT-IR, 1H-NMR spectra, scanning and transmission electron microscopy. Elemental composition of FPVPC has been deduced qualitatively through laser-induced breakdown spectra using a Q-switched Nd: YAG laser emitting at 1,064 nm, with 28 nanoseconds pulse duration as excitation source. Effect of C60 content on thermal properties of FPVPC has been studied through simultaneous thermogravimetric-differential thermal analysis- differential thermogravimetry and differential scanning calorimetry. Copyright © Taylor & Francis Group, LLC. Source

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