Indian Journal of Chemical Technology

 

VOLUME 8

NUMBER 6

NOVEMBER 2001

 

CONTENTS

 

Papers

 

Investigation of the non-pair formation of palladium (II) with N-n-octylaniline by solvent extraction from weak organic acid media

 

445

  S S Kolekar & M A Anuse

 

 

 

Thin-layer chromatography of heavy metal-diethyl dithiocarbamate complexes

452

  B R Rao, H S Rathore, S Mital & Y N Singh

 

 

 

Retention behaviour and mechanism of adsorption of some chloropyridine isomers in normal phase liquid chromatography on silica, cyano-silica and amino-silica columns

 

 

458

  A S R Krishnamurthy & R Narsimha

 

 

 

Corrosion inhibition of mild steel in sulphuric acid by n-octylamine and
iodoacetic acid

 

463

  S Shabanna Begum, R Subramanian, V Lakshminarayanan & S M Mayanna

 

 

 

Isopropylation of naphthalene over large pore zeolites

469

  Ishwarya Mathew, Smita Sabne, S Mayadevi, S A Pardhy & S Sivasanker

 

 

 

Rheological behaviour of fatty acid methyl esters

473

  A Srivastava & R Prasad

 

 

 

Modifications of ZSM-5 zeolite catalyst for dimethyl ether conversion to olefins

482

  Framcoise Duprat & Victor Cruz Morales

 

 

 

Hexavalent chromium removal using iron bearing industrial sludges

487

  I B Singh & D R Singh

 

 

 

Degradation of basic yellow auramine O-A textile dye by semiconductor photocatalysis

 

496

  A Pandurangan, P Kamala, S Uma,  M Palanichamy & V Murugesan

 

 

 

Design of commercial batch fractionating columns for separation of - & b- pinenes from turpentine oil by the simple method developed

 

500

  J K Sama & P Bandopadhyay

 

 

 

Phase transfer catalysed polymerisation of butyl methacrylate using potassium peroxydisulphate as initiator-A kinetic study

 

510

  M J Umapathy & D Mohan

 

 

 

Notes

 

Synthesis and characterization of new polycrown ether (schiff base)

515

  Pradip Kumar Dutta

 

 

 

Educator

 

The history of iodine from discovery to commodity

518

  Jaime Wisniak

 

 

 

Index

527

 

 

 

 

 

Indian Journal of Chemical Technology

Vol. 8, November 2001, pp. 445-451

 

 

 

Investigation of the ion-pair formation of palladium(II) with N-n-octylaniline by solvent extraction from weak organic acid media

S S Kolekar & M A Anuse

The use of N-n-octylaniline in xylene for extraction of palladium(II) from salicylate media is studied. The extraction system is studied as a function of equilibration time, diluent, pH, metal and extractant concentrations. Experimental data have been analyzed graphically to determine the stoichiometry of extracted species. It was found that palladium(II) was extracted into the organic phase by ion-pair formation of the [RR’NH2+ Pd(C7H5O3)3-]org. The method is free from interferences due to commonly associated elements and permits the separation of palladium(II) from other metal ions associated with it. The results are employed in the determination of the metal ions in several synthetic mixtures, alloys and catalyst samples.

Indian Journal of Chemical Technology

Vol. 7, November 2001 pp.452-457

 

 

Thin-layer chromatography of heavy metal-diethyl dithiocarbamate complexes

B R Rao, H S Rathore, S Mital & Y N Singh

Thin-layer chromatographic behaviour of some heavy metal-diethyldithiocarbamate complexes has been studied using calcium carbonate, calcium citrate, calcium oxalate, calcium phosphate dibasic, calcium sulphate dehydrated, cellulose and silica gel G as stationary phase and acetonitrile, acetone, benzene, butanol, chloroform, 1,4-dioxan, distilled water, ethyl acetate, EDTA-ammonia buffer (1:1), methanol and propanol as mobile phase. Cd(II) and Pb(II) from Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Hg(I) and Hg(II) have been practically separated on cellulose impregnated with sodium diethyldithiocarbamate in ethyl acetate.

 

Indian Journal of Chemical Technology

Vol. 7, November 2001 pp.458-462

 

 

Retention behavior and mechanism of adsorption of some chloropyridine isomers in normal phase liquid chromatography on silica, cyano-silica and amino-silica columns

A S R Krishnamurthy & R Narsimha

The retention behaviour of some chloropyridine isomers on silica, cyano-silica and amino-silica columns in normal phase liquid chromatography has been studied. Retention times on first two columns follow similar pattern while is different on amino-silica column. An equation for inter comparison of columns for selectivity purpose is developed and verified. Log kversus log XB plots follow Snyder and Soczewinski model of adsorption. A mixed interaction of involving hydrogen bonding and dipolar interactions are responsible for the retention of solutes on silica and cyano-silica columns and weak hydrogen bonding interaction lead to separation on amino-silica column. Cyano-silica column is preferred for their separation considering the retention times. However, best selectivity is seen for monoisomers and 2,6-DCP on either silica or cyano-silica column and 3,5-DCP and 2,3,5-TCP on amino-silica column.

 

Indian Journal of Chemical Technology

Vol. 8, November 2001, pp. 463-468

 

Corrosion inhibition of mild steel in sulphuric acid by n-octylamine and iodoacetic acid

S Shabanna Begum, R Subramanian, V Lakshminarayanan & S M Mayanna

The influence of iodoacetic acid (IAA) on the corrosion inhibition of mild steel in 0.5 M sulphuric acid (H2SO4) containing octylamine (OA) has been studied using weightloss, polarization and a.c. impedence techniques. Corrosion data obtained by different methods are consistent. IAA and OA individually retard the corrosion of mild steel in sulphuric acid. The addition of IAA enhances the inhibitor efficiency of OA considerably. Adsorption of inhibitors follows quasi-substitution process at the interfaces. OA cations are adsorbed by coulombic interaction on the metal surface, which is pre-occupied by IAA molecules as dipoles. Adsorption model is suggested to account the synergistic action of IAA on the corrosion inhibition of mild steel in sulphuric acid solution by OA.

 

Indian Journal of Chemical Technology

Vol. 8, November 2001, pp. 469-472

 

 

Isopropylation of naphthalene over large pore zeolites

Ishwarya Mathew, Smita Sabne, S Mayadevi, S A Pardhy & S Sivasanker

 

Isopropylation of naphthalene with isopropanol (IPA) proceeds at 2000C over the large pore zeolites HY, Hb, H-Mordenite and REY in the presence of N2. Over Hb, conversion is more in N2 than when cyclohexane is used as solvent or in absence of N2. Conversions and selectivities to diisopropyl naphthalenes fall in the sequence Hb > REY > HM > HY, but 2,6: 2,7 ratio is greatest with HM. With Hb, conversion is maximum at 2000C, and increasing the IPA : naphthalene ratio leads to deactivation of the catalyst.

 

Indian Journal of Chemical Technology

Vol. 8, November 2001, pp. 473-481

 

Rheological behaviour of fatty acid methyl esters

A Srivastava & R Prasad

Rheology of fatty acid methyl esters of soyabean, used-soyabean, mustard and used-mustard oils has been examined experimentally in the temperature range of -3 to 15°C. Such a low temperature is encountered in the use of these fatty esters as diesel fuels. These fatty esters were prepared in the laboratory by the transesterification of oils with methanol in the presence of sodium hydroxide as a catalyst. Brookfield Synchro-Lectric Viscometer has been used to observe the dependence of shear rate, time, temperature on the apparent viscosity of these fatty esters. Kerosine works satisfactorily as the bath fluid in the Ultra Cryostat for the desired temperature range. The fatty acid methyl esters of soyabean, used-soyabean, mustard and used-mustard oils are found to behave as Newtonian fluids above a temperature of about 5°C. Below this temperature, they are expected to behave as pseudoplastic fluids. These methyl esters also exhibit a thixotropic behaviour. The decrease in the apparent viscosity of these methyl esters with increase in temperature is approximately exponential.

 

Indian Journal of Chemical Technology

Vol. 8, November 2001, pp. 482-486

 

 

Modifications of ZSM-5 zeolite catalyst for dimethyl ether conversion to olefins

Françoise Duprat & Victor Cruz Morales

The influence of modifications of the ZSM-5 catalyst on the conversion of dimethyl ether to olefins is studied at low hydrocarbon conversion in order to explore the possibility of selective formation of C4=-C6=. Three modifications designed in order to reduce catalyst acidity without increasing steric hindrance are compared, namely, dealumination, partial neutralization with ammonia and ion-exchange with lithium. The unmodified H-ZSM-5 produces 60 % of ethene and propene, 30 % of olefins C4=-C6= and 10 % of heavy olefins plus aromatics. In the same conversion range, the three modified catalysts promote the formation of C4=-C6= and even more the formation of C7=-C8=, and they lower the formation of light olefins and aromatics. There is only a slight difference between modified catalysts : lithium exchanged ZSM-5 leads to higher ratio of C4=-C6= to heavy by-products. An enhanced diffusivity in modified catalysts probably plays a role in the increase in the average molecular weight of olefins produced.

 

Indian Journal of Chemical Technology

Vol. 8, November 2001, pp. 487-495

 

 

Hexavalent chromium removal using iron bearing industrial sludges

I B Singh & D R Singh

The use of iron bearing metallic and mineral materials for the treatment of highly toxic Cr(VI) containing industrial wastewater have received increased attention for the past decade. In conventional treatment, a large amount of chromium hydroxide generates as secondary solid waste which poses a serious problem of disposal. In the presence of iron bearing materials, Cr(VI) reduces to Cr(III) and Fe(II) oxidises to Fe(III) generating mixed complexes from which separation probability of individual element reduces. Based on this chemical principle it is expected that such industrial solid wastes containing iron as a major constituent have potential to reduce highly toxic Cr(VI) to less toxic Cr(III). In view of this, present investigation was aimed to utilise iron bearing industrial wastes like sludges of steel tube making industry and aluminium industry for removal of Cr(VI). Studies include identification of suitable pH for the Cr(VI) reduction, optimisation of dosage and contact time and determination of reaction kinetics. No Cr(VI) was detected from the reacted wastes and total chromium was measured as Cr(III).Toxicity characteristics leaching procedure(TCLP) has been employed to estimate the leachability of chromium, iron etc from the reacted wastes. TCLP results indicate a negligible amount of chromium as Cr(III) and iron leachability from the reacted wastes.

 

Indian Journal of Chemical Technology

Vol. 8, November 2001, pp. 496-499

 

Degradation of basic yellow auramine O-A textile dye by semiconductor photocatalysis

A Pandurangan, P Kamala, S Uma, M Palanichamy & V Murugesan

 

Indian Journal of Chemical Technology

Vol. 8, November 2001, pp. 500-509

Design of commercial batch fractionating columns for separation of
a- & b-pinenes from turpentine oil by the simple method developed

J K Sama & P Bandopadhyay

A commercial batch fractionating column, for separating a- & b-pinenes from a multicomponent mixture, such as tupentine oil was designed, installed and commissioned. The practical results obtained speak well of the accuracy of the simple graphical method developed for designing such columns and calculations for isolating different components.

 

 

Indian Journal of Chemical Technology

Vol. 8, November 2001, pp. 510-514

 

 

Phase transfer catalysed polymerisation of butyl methacrylate using potassium peroxydisulphate as initiator ¾ A kinetic study

M J Umapathy & D Mohan

The kinetics of phase transfer catalysed free radical polymerisation of butyl methacrylate using potassium peroxydisulphate as water soluble initiator and propiophenonebenzyldimethylammonium chloride (PPBDAC) as phase transfer catalyst were studied. The polymerisation reactions were carried out in cyclohexanone-water biphase media at 60°C in an inert atmosphere under unstirred condition. The effect of various experimental conditions such as different concentrations of monomer, initiator, phase transfer catalyst (PTC) and different ionic strength, temperature and the volume fraction of aqueous phase is studied. The order with respect to monomer, initiator and the phase transfer catalyst is found to be 1, 0.5 and 0.5 respectively. The rate of polymerisation (Rp) is independent of ionic strength and pH. However, an increase in the polarity of solvent and volume fraction of aqueous phase slightly increases the Rp value. Based on the results obtained, a mechanism has been proposed for the polymerisation reaction.

 

 

Indian Journal of Chemical Technology

Vol. 8, November 2001. pp. 515-517

 

 

 

Synthesis and characterization of new polycrown ether (schiff base)

Pradip Kumar Dutta

A semirigid 32-membered ring dialdehyde crown ether, bis (5-aldoxy-1, 3-phenylene)-32-crown-10 (3), has beensynthesized in one step using 3,5-dihydroxy benzaldehyde (1) and tetra (ethylene glycol) dichloride (2) in the presence of sodium hydride in DMF. A direct polycondensation reaction of bis (5-aldoxy-1,3-phenylene)-32-crown-10(3) and diamines (5) in DMF formed a high molecular weight poly crown ether (schiff base). The polymers are characterized by viscometry, elemental analysis, IR and NMR spectroscopies. The polymers are soluble in common organic solvents. The thermal characteristics of the polymers have been studied by TGA and DTA.

 

 

Indian Journal of Chemical Technology

Vol. 8, November 2001, pp. 518-526

 

 

The History of Iodine From Discovery to Commodity

Jaime Wisniak

Department of Chemical Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel 84105

The discovery of iodine by accident and the turning of this event into its industrial manufacturing constitutes a fascinating chapter in the development of chemical technology. We see in it how political and economical events brought drastic changes in the raw materials used and the production technologies. From a strictly European activity it turned into an important economic commodity for Chile and Japan.