Papers by Prof. Manas Chanda
Journal of the Indian Institute of Science, 2013
A procedure is presented for chooing over-relaxation factor w when we do not posses any knowledge... more A procedure is presented for chooing over-relaxation factor w when we do not posses any knowledge of it. This relaxtion factor however does ,not represent the conventinal sealar mairix in the matrix notarion. Insted, it represents a dagonal matrix having the form diag(w 1..1)A linear system Ax = b is considered for illustration. A few examples worked out by one-srep cyclic process (Gmss-Seiihl rn~thod) and obo by over-relaxajion method (with the over-relaxation facyor obtained in the aforesaid manner) irdicate a much more rapid convrrgurice characteristic of the latter process.
Journal of the Indian Institute of Science, 2013
The puttern of acetylene conversion in the hydropolymerization reaction over palladium catalyst i... more The puttern of acetylene conversion in the hydropolymerization reaction over palladium catalyst in fixed bed has been studied and the effects of varying the palladium concentration and of incorporating ZnO-Cr2O3 additve in the catalyst have been determined The effect of feed dilution with inert nirgen on the conversion pnitern hus been studied. Conversion data on the hydropolymentsation reaction carried over Pd-ZnO-Cr2O3 Kieselguhr (0 02 : 5.0 : 4.6 : 100) catalyest have been Processed in respect qf reaction temperature space velocity and feed gas composition as variables. Results lead to the conclusions conclusions that acctylene conversion to ethylene, butarliene, and oil are primrury reactions, while butenes are secondary products stenning from primarily proriured buiadiene.
Journal of the Indian Institute of Science, 2013
Presented in this paper is a simple extrapolation technique to obtain numerical derivative of an ... more Presented in this paper is a simple extrapolation technique to obtain numerical derivative of an analytic function, complex or real. The function may be in tabular form or in functional form. A few numerical examples are added for the purpose of illustration.
Reactive Polymers, 1989
Glyoxal-bis-2-hydroxyanil (GHA) has been reacted with formaldehyde and salicylaldehyde-ethylenedi... more Glyoxal-bis-2-hydroxyanil (GHA) has been reacted with formaldehyde and salicylaldehyde-ethylenediimine (SED) with a mixture of resorcinol and formaldehyde, to prepare the phenolic-type resins Poly(GHA) and Poly(SED), which have high sorption capacities for UO 2+ (455 and 334 mg U/g dry weight of resin) and for Fe 3+ (245 and 77 mg Fe/g dry weight of resin). The sorption of UO 2 + is maximum in weakly acidic or neutral solutions (pH 6-7), falling rapidly both at lower and higher pH, while the uptake of Fe 3 +, sorbed mainly as anionic complexes, is high even in strongly acidic HCl and H2SO 4 media. Among other common transition metal ions, only Cu(II) has significant sorption on Poly(GHA) and Poly(SED), the saturation capacities being 61 and 31 mg Cu/g dry weight of resin, respectively. Considering the sea water concentrations of transition metal ions as the equilibrium concentrations in the presence of the resin, concentration factors have been calculated for UO ff + (as tricarbonate complex) and common transition metal ions, yielding the highest values for UO ] + with 68 and 39 L sea water / g dry weight of resin on Poly(GHA) and Poly(SED), respectively.
1 Struktur Atom 2 Ikatan Kimia Atomic Structure and Chemical Bond Including Molecular Spectroscopy Manas Chanda, 1991
Science of Engineering Materials, 1980
Science of Engineering Materials, 1979
Industrial & Engineering Chemistry Process Design and Development, 1976
Supplementary Material Available. An expanded version of the article (15 pages plus 5 figures). O... more Supplementary Material Available. An expanded version of the article (15 pages plus 5 figures). Ordering information is given on any current masthead page.
Plastics Engineering, 2016
Fabrication Processes Types of Processes Tooling for Plastics Processing Compression Molding Tran... more Fabrication Processes Types of Processes Tooling for Plastics Processing Compression Molding Transfer Molding Injection Molding of Thermoplastics Injection Molding of Thermosetting Resins Extrusion Blow Molding Calendering Spinning of Fibers Thermoforming Casting Processes Reinforcing Processes Reaction Injection Molding Structural Reaction Injection Molding Resin Transfer Molding Foaming Processes Rubber Compounding and Processing Technology Miscellaneous Processing Techniques Decoration of Plastics Recycling of Polymers Introduction Outline of Recycling Methods Recycling of Poly(Ethylene Terephthalate) Recycling of Polyurethanes Recycling of Poly(Vinyl Chloride) Recycling of Cured Epoxies Recycling of Mixed Plastics Waste Post-Consumer Polyethylene Films Recycling of Ground Rubber Tires Recycling of Car Batteries Plastic Recycling Equipment and Machinery Appendices Index of Trade Names and Suppliers of Foaming Agents Formulations of Polyurethane Foams Formulations of Selected PVC Compounds Formulations of Selected Rubber Compounds Commercial Polymer Blends and Alloys Index References appear at the end of each chapter.
Journal of Polymer Science Part A: Polymer Chemistry, 1989
Microporous polybenzimidazole of 250–500 μm spherical bead size from Celanese has been reacted wi... more Microporous polybenzimidazole of 250–500 μm spherical bead size from Celanese has been reacted with epichlorohydrin and sodium hydroxide and the resulting product with pendant epoxy groups has been reacted with various chelating ligands in order to augment the metal sorption capacity and selectivity of the resin. The chelating ligands used include ethylenediamine, diethylenetriamine, diethanolamine, dimethylglyoxime, L‐cysteine, thiourea, dithiooxamide, glyoxal‐bis‐2‐hydroxyanil, salicylaldehyde‐ethylenediimine, and glyoxal‐bis‐2‐mercaptoanil. The aminolysis of the pendant epoxy groups with the oligoamines has been performed in pyridine under reflux conditions, while the addition reactions with the other ligands which are alkali soluble have been carried out at room temperature in a mixture of dioxane and aqueous KOH using tetra‐n‐butylammonium iodide as the phase transfer catalyst. The products are found to possess high capacity and selectivity in metal sorption depending on the li...
Journal of Applied Polymer Science, 1979
Several samples of poly(viny1 formal) having the same vinyl alcohol content (84%) but varying con... more Several samples of poly(viny1 formal) having the same vinyl alcohol content (84%) but varying contents of vinyl acetate (6-22%) and vinyl formol(70-85%) were prepared and subjected to thermogravimetric analysis, in air and nitrogen atmospheres, employing both isothermal and dynamic methods. Kinetic parameters determined from both the isothermal and dynamic TGA data are compared. The activation energy is seen to be largely dependent on the degree of conversion, implying a complex degradation reaction. The activation energy is also much less for degradation in air than in nitrogen, which can be explained by a reaction with oxygen-producing structures favoring degradation. The activation energy is less sensitive to variation in polymer composition for degradation in air than in nitrogen. Thus, in the dynamic process, the activation energy value decreases (from 36 to 23 kcal/mole) with increasing acetate content (from 6 to 22%) in nitrogen atmosphere, while in air the activation energy value increases only moderately (from 21 to 27 kcal/mole) with increasing acetate content (from 6 to 22%). The order of reaction is nearly unity, irrespective of the composition of the polymer, both in air and nitrogen.
Journal of Applied Polymer Science, 1993
A kinetic model has been developed on the basis of reaction mechanisms proposed for the anhydride... more A kinetic model has been developed on the basis of reaction mechanisms proposed for the anhydride curing of diepoxides, using tertiary amine as catalyst. The model has been tested for the cure reaction of a diglycidylester model compound, bis‐(2,3‐epoxypropyl)‐1,3‐benzenedicarboxylate, with hexahydrophthalic anhydride as the curing agent and benzyldimethylamine as the catalyst, over the temperature range 100–120°C, the rate being measured by means of differential scanning calorimetry, using an isothermal approach. The rate expressions derived for the model are half order and first order, with respect to reacted and unreacted functional groups, respectively, in the initial stage. For the later stage of curing, up to the point of vitrification, the model indicates a 1.5 order with respect to the unreacted functional groups. These are in good agreement with the kinetic orders of 0.5 and 1.5, with respect to reacted and unreacted functional groups, respectively, reported earlier from a ...
Journal of Applied Polymer Science, 1993
The cure reaction of a model diglycidyl ester, bis‐(2,3‐epoxypropyl)‐1,3‐benzenedicarbox‐ylate, w... more The cure reaction of a model diglycidyl ester, bis‐(2,3‐epoxypropyl)‐1,3‐benzenedicarbox‐ylate, with hexahydrophthalic anhydride as the curing agent and benzyldimethylamine as the catalyst, was studied by differential scanning calorimetry using an isothermal approach over the temperature range 100–135°C. The results indicate that the cure reaction is au‐tocatalytic in nature and does not follow simple nth‐order kinetics. A semiempirical equation for autocatalytic systems containing two rate constants and two reaction orders, viz., 0.5 and 1.5, provided a good phenomenological description of the cure kinetics up to the point of vitrification. With the inclusion of a diffusion factor into this model, it was, however, possible to predict with precision the cure kinetics over the whole range of conversion covering both pre‐and postvitrification stages and over the entire temperature range of 100–135°C employed for isothermal curing. © 1993 John Wiley & Sons, Inc.
Industrial & Engineering Chemistry Research, 1995
A new process has been developed for making granular gel-type sorbents from chelating resins usin... more A new process has been developed for making granular gel-type sorbents from chelating resins using metal ion as template. Named as templated gel-filling, the process uses the chosen metal as templating host ion on high-surface-area silica to build a templated gel layer from a solution of the chelating resin in a suitable solvent in which the resin is soluble but its metal complex is insoluble. After cross-linking the templated gel layer, the silica support is removed by alkali to produce a hollow shell of the templated gel. The shells are then soaked in a concentrated aqueous solution of the same metal ion and suspended in the same resin solution to afford gel-filling. The shells thus filled with metal-templated gel are treated with cross-linking agent, followed by acid to remove the template ion and activate the resin for metal sorption. Poly(ethy1ene imine) and its partially ethylated derivative have been used to produce granular gel-type sorbents by this process, with Cu(I1) as the template ion. These sorbents are found to offer high capacity and selectivity for copper over nickel, cobalt, and zinc in both acidic and alkaline media. Containing a relatively high fraction of imbibed water, the sorbents exhibit markedly enhanced rate behavior, in both sorption and stripping.
A novel vinyl monomer with an isocyanate functional group, m-isopropenyl-alpha,alpha-dimethylbenz... more A novel vinyl monomer with an isocyanate functional group, m-isopropenyl-alpha,alpha-dimethylbenzyl-isocyanate (m-TMI), was grafted onto isotactic polypropylene (i-PP) using dicumyl peroxide (DCP) as the initiator. This would open up the possibility of using the grafted polymer with the reactive isocyanate group as compatibilizer for blending carbohydrates such as cellulose with. polypropylene. The grafting was carried out in a Brabender Plasticoder at 180degreesC. The effects of monomer and initiator concentrations on the yield of grafting were investigated by performing statistical analysis. While the grafting yield increased with the concentration of DCP at any given concentration of m-TMI, the variation of the grafting yield with m-TMI concentration, for a given concentration of DCP, went through a maximum, the optimum yield of 7.8% (w/w) being obtained at 10 wt.% concentration of both DCP and m-TMI. The grafting reaction is. accompanied by considerable chain scission of I-PP, resulting in a decrease in the molecular weight of the grafted polymer. While the molecular weight drops sharply even at a low concentration of DCP, there occurs no further significant change in the molecular weight even at much higher concentrations of the initiator.
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Papers by Prof. Manas Chanda