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Indian Journal of Chemical Technology

 

 

 

ISSN:0971-457X

CODEN:ICHTEU 12(1) 1-130

VOLUME 12

 NUMBER 1

JANUARY 2005

 

CONTENTS

 

 

 

Research articles

Preservation of bagasse through the application of chemical preservatives

7

IPC Code: B27K 9/00; D21B 1/02

 

K R Yadav, A B Chaudhari, R K Sharma & R M Kothari

 

 

 

Application of 2-nitroso-1-naphthol-4-sulphonic acid for separation and preconcentration of trace cadmium and determination by differential pulse polarography

 

12

IPC Code: G01N 27/48

 

Mohammad Ali Taher, Sayed Ziae Mohammadi Mobarakeh & Fatameh Saber Mahani

 

 

 

Degradation of ferrohexacyanide by advanced oxidation processes

19

IPC Code: C07B 33/00

 

Sarla Malhotra, M Pandit & D K Tyagi

 

 

 

Sensitive titrimetric and spectrophotometric assay methods for chlorpromazine with bromate-bromide mixture and two dyes

 

25

IPC Code: G01J 3/00; C07D 279/00; A61K

 

K Basavaiah, P Nagegowda, H C Prameela & B C Somashekar

 

 

 

Reactivity assessment of non-coking coal by oxidative thermogravimetric studies

30

IPC Code: C10B 47/00

 

Pushpa Singh, Nandita Choudhury, A Sarkar, P Sarkar & T B Das

 

 

 

Effect of non-ionic micellar aggregates on the kinetics of oxidation of aminoalcohols by N-bromosuccinimide in alkaline medium

35

IPC Code: C07B 33/00

 

Shalini Pandey & Santosh K Upadhyay

 

 

 

Mechanistic studies of saponification of some mono – and di-esters of carboxylic acids through iso-kinetic relationships (DH #DS D #) in protic and aprotic solvent systems

43

IPC Code: C07C 27/02

 

B M Rao & K Gajanan

 

 

 

Effectiveness of bis(2-methylpiperazine dithiocarbamato) Cu(11) and Zn(11), bis(di-ethyl-dithiophosphato) Ni(11) and its n-pico-Line diadduct and bis(pyrrolidine dithio-carbamato) Cu(11) as antioxidant lubricating oil additives

50

IPC Code: C10M 125/06

 

Pradip K Gogoi & Juthika Sonowal

 

 

 

Synthesis of chemical additives and their effect on Akholjuni crude oil (Gujarat, India)

55

IPC Code: C10L 1/10

 

Hemant P Soni, D P Bharambe, A Nagar & Kiranbala

 

Free radical copolymerization of limonene with butyl methacrylate: Synthesis and characterization

62

IPC Code: C08F 2/00

 

Saroj Sharma & A K Srivastava

 

 

 

Photocatalysed degradation of a fungicide, thiram in aqueous suspension of titanium dioxide

68

IPC Code: C02F 1/00

 

M M Haque & M Muneer

 

 

 

Photocatalytic degradation of 3,4-dichlorophenol using Tio2 in a shallow pond slurry reactor

75

IPC Code: C02F 1/36

 

Amrit Pal Toor, Anoop Verma, Chand K Jotshi, Pramod K Bajpai & Vasundhara Singh

 

 

 

PET waste based polyurethane adhesive for rubber joints

82

IPC Code: B29B 7/00; C09J

 

S D Desai, J V Patel, M R Patel & V K Sinha

 

 

 

Assessment of thickness-dependent gas permeability of polymer membranes

88

IPC Code: B01D 71/00

 

M A Islam & H Buschatz

 

 

 

Prevention of metallic corrosion by some salts of benzoic hydrazide under vapour phase conditions

93

IPC Code: C07C 243/00; C23F 11/10

 

M A Quraishi, V Bhardwaj & D Jamal

 

 

 

Heterocyclic anils as corrosion inhibitors of mild steel in formic and acetic acid solutions

98

IPC Code: C23F 11/08

 

M A Quraishi & H K Sharma

 

 

 

Note

 

Effect of gamma radiation on solution viscosity of galactomannans: Influence of galactose mannose ratio

105

IPC Code: G05D 24/00

 

Roshan Issarani & B P Nagori

 

 

 

Educator

 

Phosphorus – From discovery to commodity

108

Jaime Wisniak

 

Chem-Tech Scan
 123
Author Index
127
Keyword Index
128
Announcement  
130

                                                                                                            

     

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp. 7-11

 

Preservation of bagasse through the application of chemical preservatives

K R Yadav, A B Chaudhari, R K Sharma & R M Kothari*

 

Exposure of bagasse to 8 industrial preservatives such as sodium meta bisulphite (reducing agent), calcium hypochlorite and iodine (oxidizing agents) and Contaf-5E, Celphos, BU-30, liquid ammonia and quat-2C (broad spectrum fumigants/fungicides) was explored for its preservation at 200 kg scale for 6 months under ambient conditions, mimicking pulp and paper mill practices. Bacterial and fungal count, fiber and pith content, temperature, pH, reducing sugars (soluble content) and brightness were monitored at monthly frequency to judge the efficacy of the above preservatives. Among them, only Celphos appeared to be superior to others, besides being cost-effective, eco-friendly and practical preservative on the basis of parameters monitored. Its application is suggested until better preservative is identified.

Keywords: Bagasse preservation, chemical preservatives, superior pulp.

IPC Code: B27K 9/00; D21B 1/02

 

 

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp. 12-18

 

Application of 2-nitroso-1-naphthol-4-sulphonic acid for separation and preconcentration of trace cadmium and determination by differential pulse polarography

Mohammad Ali Taher*, Sayed Ziae Mohammadi Mobarakeh & Fatameh Saber Mahani

 

A highly selective, sensitive, rapid and economical differential pulse polarographic method has been developed for the determination of trace amount of cadmium in various standard alloys and biological samples after adsorption of its 2-nitroso-1-naphthol-4-sulphonic acid - tetradecyldimethylbenzylammonium chloride on microcrystalline naphthalene in the pH range of 5.7-11.0. After filtration, the solid mass is shaken with 9.0 mL of 1 M hydrochloric acid and cadmium is determined by differential pulse polarography (DPP). Cadmium can alternatively be adsorbed on 2-nitroso-1-naphthol-4-sulphonic acid-tetradecyldimethylbenzylammonium-naphthalene adsorbent packed in a column and determined. In this case, 0.9 mg of cadmium can be concentrated in a column from 300 mL of aqueous sample, where its concentration is as low as 3 ng/mL. Characterization of the electroactive process included an examination of the degree of reversibility. Various parameters such as the effect of pH, volume of aqueous phase, HCl concentration, reagent concentration, naphthalene concentration, shaking time and interference of a number of metal ions on the determination of cadmium have been studied in detail to optimize the conditions for determination in standard alloys and standard biological samples.

Keywords: Differential pulse polarography, cadmium determination, standard alloys, biological samples, 2-nitroso-1-naphthol-4-sulphonic acid.

IPC Code: G01N 27/48

 

 

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp. 19-24

 

Degradation of ferrohexacyanide by advanced oxidation processes

 Sarla Malhotra*, M Pandit & D K Tyagi

 

Degradation of ferrohexacyanide in aqueous solution by advanced oxidation processes was studied. Advanced oxidation processes included ozone and its combination with H2O2 and ultraviolet radiation (UV). Results demonstrated that UV alone was not sufficient to degrade cyanide ion but an oxidant was required for complete degradation. Degradation of 100 mg/L cyanide in aqueous solution was pseudo-first order reaction at pH 11.0. Lower pH was avoided due to formation of HCN gas but higher pH favoured the degradation. A comparison of three systems i.e. O3, O3/H2O2 and UV/O3/H2O2 showed that UV/O3/H2O2 was the best system. The experimental results showed that the optimum conditions for UV/O3/H2O2 process for total cyanide degradation were obtained at l = 365 nm (400 W medium pressure UV lamp), ozone concentration = 35 mg/L and H2O2 = 88.2 mM.

Keywords: Degradation, ferrohexacyanide, UV-radiation, ozone, hydrogen peroxide

IPC Code: C07B 33/00

 

 

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp. 25-29

 

Sensitive titrimetric and spectrophotometric assay methods for chlorpromazine with bromate-bromide mixture and two dyes

 K Basavaiah*, P Nagegowda, H C Prameela & B C Somashekar

 

Three new methods using titrimetry and spectrophotometry are described for the determination of chlorpromazine hydrochloride with bromate-bromide mixture as the oxidimetric-brominating agent and two dyes, methyl orange and indigo carmine. In titrimetry (method A), the drug is treated with a measured excess of bromate-bromide reagent in acid medium, and the residual bromine is determined iodometrically. The two spectrophotometric methods involve the addition of a measured excess of bromate-bromide mixture to drug solution in acidic conditions followed by estimation of the unreacted bromine by treating with a fixed amount of methyl orange (method B) or indigo carmine (method C) and measuring the absorbance at 520 nm (method B) or 610 nm (method C). Titrimetric procedure is applicable over 1-10 mg range and the reaction stoichiometry is found to be 1:1 (drug: bromate). In spectrophotometric methods, the systems obey Beer’s law over 1.0-6.0 mg mL-1 and 2.5-15.0 mg mL-1, for methods B and C, respectively. The molar absorptivity and Sandell sensitivity values and the limits of detection and quantification are reported for both spectrophotometric methods. The proposed methods were applied to the determination of chlorpromazine hydrochloride in tablets and injections with the assay results in the range of 98.63 to 101.88% of label claim. The reliability of the methods was assessed by parallel determination by the official method and by recovery studies.

 

Keywords: Chlorpromazine determination, titrimetry, spectrophotometry, bromate-bromide, dyes.

IPC Code: C07D 279/00; G01J 3/00; A61K

 

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp 30-34

 

Reactivity assessment of non-coking coal by oxidative thermogravimetric studies

Pushpa Singh, Nandita Choudhury, A Sarkar, P Sarkar & T B Das*

 

Inertinite rich low rank coal has been found to be more reactive than vitrinite rich high rank coal. In the present investigation, reactivity assessment studies were conducted on two high ash, non-coking bituminous coals of Indian origin. The reactivity of the derived chars were also measured in kinetic regime-I by both non-isothermal and isothermal gravimetric analysis. The reactivities of the parent coals and the prepared chars were assessed from burning profiles, crossing point/ignition point temperature measurement and calculated activation energies. A discussion is presented to find the relationship between reactivity parameters and coal rank, maceral composition, char morphology and atomic H/C ratio of chars. The low temperature reactivity was found to have good relationship with coal rank and atomic H/C ratio of the chars.

 

Keywords: Reactivity, pyrolysis char, thermogravimetry, petrography

IPC Code: C10B 47/00

 

 

 

Indian Journal of Chemical Technology

Vol. 11, January 2005, pp. 35-42

 

Effect of non-ionic micellar aggregates on the kinetics of oxidation of aminoalcohols by N-bromosuccinimide in alkaline medium

 Shalini Pandey & Santosh K Upadhyay*

 

The kinetics of oxidation of aminoalcohols (AA) viz ethanolamine (EA), diethanolamine (DEA) and triethanolamine (TEA) by N-bromosuccinimide (NBS) in alkaline medium have been investigated in absence and in presence of polyoxyethylene (23) lauryl ether (Brij-35), a non-ionic surfactant. The kinetics showed a first order dependence of rate in NBS while the order in each AA and alkali was found to decrease from unity to zero at higher [AA] and [OH-], respectively. The presence of small amount of surfactant strongly enhanced the rate of oxidation and the observed rate constants attained a constancy at higher surfactant concentration. The premicellar kinetics have been rationalised in the light of Piszkiewicz’s positive cooperativity model. The binding constants between the reactants and the surfactant have also been evaluated using Raghvan and Srinivasan model, which is applicable for a bimolecular micellar catalysed reaction. The binding constants obtained by both the models are in good agreement.

 

Keywords: Micellar aggregates, oxidation of aminoalcohol, kinetics of N-bromosuccinimide.

IPC Code: C07B 33/00

 

 

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp. 43-49

 

Mechanistic studies of saponification of some mono- and di-esters of carboxylic acids through iso-kinetic relationships (DH¹ vs. DS¹) in protic and aprotic solvent systems

 B M Rao* & K Gajanan

 

The mechanism of saponification of structurally related and industrially important mono- and diesters in protic and aprotic solvent systems have been investigated. Time ratio method and Swain's standard data for series first order reactions have been utilized for the evaluation of rate data and thermodynamic parameters viz. DE¹, -DH¹, DG¹, DS¹ and logA for the steps which involve the competitive and consecutive saponification reactions. Further, the enthalpy-entropy correlations are used to establish the plausible mechanism of saponification process for the esters. Comparative study of the slopes of linear plots (DH¹ vs. DS¹) reveal that dilaurates undergo faster saponification process than distearates and oleostearates irrespective of any solvent sytems. The experimental plots (DH¹ vs. DS¹) support a faster saponification process of mono esters than diesters in all the protic and aprotic solvent systems studied.

Keywords: Saponification, monoesters, diesters, mechanism

IPC Code: C07C 27/02

 

 

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp. 50-54

 

Effectiveness of bis(2-methylpiperazine dithiocarbamato) Cu(II)  and Zn(II),  bis(diethyldithiophosphato) Ni(II) and its g-picoline diadduct and bis(pyrrolidine dithiocarbamato) Cu(II) as antioxidant lubricating oil additives

Pradip K Gogoi* & Juthika Sonowal

 

Effectiveness of 2-methylpiperazinedithiocarbamato(2-Mepipzdtc) complexes of Cu(II) and Zn(II), diethyldithiophosphato (Et2dtp) complex of Ni(II) and its g-picoline diadduct, and pyrrolidine dithiocarbamato complex of Cu(II) are evaluated as antioxidant lubricating oil additives by measurement of viscosity, acid number, IR spectral and thermal studies. All the complexes at 0.25 and 0.5 wt% show antioxidant property. Zn(2-Mepipzdtc)2 as well as Ni(Et2dtp)2(g-pic)2 were found to be most effective antioxidants among these compounds. The antioxidant behaviour has been explained on the basis of hydroperoxide decomposition and radical scavenger mechanism.

Keywords:   2-methylpiperazine dithiocarbamates, pyrrolidine dithiocarbamate, diethyldithiophosphate, Cu(II), Ni(II),      Zn(II), antioxidant, oil additive.

IPC Code: C10M 125/06

 

 

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp. 55-61

 

Synthesis of chemical additives and their effect on Akholjuni crude oil (Gujarat, India)

Hemant P Soni, D P Bharambe, A Nagar* & Kiranbala

 

High paraffin wax content in crude oil creates a variety of problems during production and transportation through pipelines. One of the main problems is the crystallization and deposition of paraffin wax crystals in the flow line which is more severe in winter. Low ambient temperature relative to pour point of the crude can cause pumping problems. The pour point and rheological properties of the crude oil can be improved by adding requisite amount of a pour point depressant (PPD). The present study deals with the synthesis of copolymers of maleic anhydride and esters of n-alkyl alcohols and unsaturated acid (C11H20O2). The resulted copolymers were esterified with two moles of fatty alcohol (C19H36O8). The products were evaluated as pour point depressant and flow improver on the Akholjuni crude oil (Gujarat, India). The pour point and rheological behaviour of the crude oil with these prepared additives were studied. The results were encouraging up to the optimum length of pendant side chains of PPD.

 

Keywords: Pour point depressant (PPD), rheological properties, pour point, cloud point, plastic viscosity, apparent viscosity

IPC Code:  C10L 1/10

 

 

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp. 62-67

 

Free radical copolymerization of limonene with butyl methacrylate: Synthesis and  characterization

Saroj Sharma & A K Srivastava*

 

The radical copolymerization of monocyclic terpene namely limonene with butyl methacrylate  in xylene at 80±0.1°C for 50 min, using benzoylperoxide (BPO) as an initiator has been carried out under the inert atmosphere of nitrogen. The system follows ideal kinetics i.e. Rp a[BPO]0.5[BMA]1.0[Lim.]–1.0. The rate of polymerization (Rp) decreases as [limonene] increases, which might be due to penultimate unit effect. The overall energy of activation has been calculated as 34 kJ/mol. The formation of the copolymer is confirmed by the presence of bands at 1727 and 2956 cm–1 due to ester carbonyl of butyl methacrylate and olefinic C–H stretching of limonene, respectively. Further, the peaks at 3.8–4.2 and 5.0–5.6 d, were observed in 1H NMR spectra due to methylene proton adjacent to ester linkage of butyl methacrylate and  trisubstituted olefinic protons of limonene, respectively. The value of reactivity ratios r1(BMA) = 0.125 and r2(Lim.)= 0.026 has been calculated by using Kelen-Tüdos method. Alfrey-Price Q–e parameter for limonene has been calculated as 0.30 and –0.46. The glass transition temperature of the copolymer is determined as 35 oC.

Keywords:  Limonene, butyl methacrylate, copolymers, reactivity ratios.

IPC Code: C08F 2/00

 

 

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp. 68-74

 

Photocatalysed degradation of a fungicide, thiram in aqueous suspension of titanium dioxide

M M Haque & M Muneer*

 

Photocatalysed degradation of a fungicide derivative, thiram has been investigated in aqueous suspensions of titanium dioxide as a function of irradiation time under a variety of conditions. The degradation kinetics were studied under different conditions such as pH, catalyst concentration, substrate concentration, different types of TiO2 and in the presence of electron acceptors such as hydrogen peroxide (H2O2), potassium bromate (KBrO3) and ammonium persulphate (NH4)2S2O8 besides molecular oxygen. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst, Degussa P25 was found to be more efficient as compared to other photocatalysts tested. All the electron acceptors markedly enhanced the degradation of the compound under investigation. The efficiency of degradation was found to be slower under sunlight as compared to the artificial light source. The degradation products were analyzed by GC-MS technique and probable pathways for the formation of products are proposed.

 

Keywords: Photocatalysis, fungicide, thiram, titanium dioxide, semiconductor.

IPC Code: C02F 1/00

 

 

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp. 75-81

 

Photocatalytic degradation of 3,4-dichlorophenol using TiO2 in a shallow pond slurry reactor

Amrit Pal Toor, Anoop Verma, Chand K Jotshi, Pramod K Bajpai & Vasundhara Singh*
 

In the present study, the TiO2 mediated photocatalytic degradation of 3,4-dichlorophenol, as a model compound, has been investigated using a low cost non-concentrating shallow pond slurry reactor at laboratory scale under a variety of conditions. The degradation was studied by monitoring the change in substrate concentration employing UV-spectroscopic analysis, decrease in COD values and increase in chloride formation as a function of irradiation time. The effect of pH, catalyst loading, substrate concentration, UV intensity, aperture to volume ratio of the reactor and presence of electron acceptors such as hydrogen peroxide besides molecular oxygen, on degradation, was studied. The degradation rates were strongly influenced by some of these parameters. The optimum parameters for maximum degradation were determined. The degradation of 3,4-dichlorophenol can be emulated in sunlight using a similar large-scale shallow pond reactor for the solar detoxification in open atmosphere.

 

Keywords: Photocatalytic degradation, UV radiation, TiO2, 3,4 dichlorophenol, reaction kinetics.

IPC Code: C02F  1/36

 

 

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp. 82-87

 

PET waste based polyurethane adhesive for rubber joints

S D Desai, J V Patel, M R Patel & V K Sinha*

 

Biomaterial based polyhydric compounds were synthesized and utilized for the depolymerization of PET. Three different oligomers were synthesized by using 5, 15 and 25% PET. Depolymerized oligomers were esterified with dehydrated castor oil (DCO) fatty acids to give polyester polyols. Polyurethane adhesives were synthesized using these polyols for joining rubber-rubber assembly. Bond strength was measured by 180° peel test. Mode of failure was studied by scanning electron microscopy (SEM) analysis. Depolymerised PET oligomers, polyols and polyurethane were characterized by FTIR spectroscopy. Also, polyurethane adhesives were evaluated for their performance and chemical resistance.

 

Keywords: PET based polyols, polyurethane adhesive, rubber joints, depolymerized oligomers.

IPC Code: B29B 7/00; C09J

 

 

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp. 88-92

 

 Assessment of thickness-dependent gas permeability of polymer membranes

M A Islam* & H Buschatz

 

Morphological changes with thickness, and the subsequent effect on the membrane permeability have been discussed qualitatively. It is concluded that some morphological elements favor transport and some hinder. Flux models based on interface reaction have been successfully applied to describe quantitatively the thickness-dependence of the membrane-permeability and the model parameters (diffusion transport coefficient, surface reaction constants) evaluated.

 

Keywords: Membrane thickness, gas permeabiliy, Fick’s law, diffusion equation, sorption-desorption rates.

IPC Code: B01D 71/00; G01N 15/00

 

 

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp. 93-97

 

Prevention of metallic corrosion by some salts of benzoic hydrazide under vapour phase conditions

M A Quraishi*, V Bhardwaj & D Jamal

 

Three volatile corrosion inhibitors (VCIs) namely, benzoic hydrazide benzoate (BHB), benzoic hydrazide salicylate (BHS), and benzoic hydrazide nitrobenzoate (BHN), were synthesized and evaluated as corrosion inhibitors of mild steel, brass and copper by weight loss method. Eschke test method, sodium chloride inoculation test method and sulphur dioxide (SO2) test method were also carried out to investigate the corrosion inhibiting effect of the compounds. All the investigated VCIs exhibited good inhibition efficiency (IE) for all the metals. Benzoate salt showed best result among all the studied compounds for all the metals.

 

Keywords: Brass, copper, benzoic hydrazide, mild steel, volatile corrosion inhibitor.

IPC Code: C07C 243/00; C23F 11/10

 

 

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp.98-104

 

Heterocyclic anils as corrosion inhibitors of mild steel in formic and acetic acid solutions

 M A Quraishi* & H K Sharma

 

Effects of four corrosion inhibitors namely, 4-(N, N-dimethylamino) benzylidine imino-3-propyl-5-mercapto-1,2,4-triazole(DIPMT), 4-benzylidine imino-3-propyl-5-mercapto-1,2,4-triazole (BIPMT), 4-salicylidene imino-3-propyl-5-mercapto-1,2,4-triazole (SIPMT) and 4-cinnamalidene imino-3-propyl-5-mercapto-1,2,4-triazole (CIPMT) against corrosion of mild steel in aqueous solutions of 20% formic acid and 20% acetic acid using weight loss and potentiodynamic polarization and impedance methods were studied. All tested inhibitors showed good inhibition efficiency (IE). The IE was found to vary with concentration, temperature, immersion time, and concentration of acid solution. The potentiodynamic polarization results revealed that all the compounds were mixed type inhibitors. The adsorption of these compounds on the mild steel surface exposed to both acids has been found to obey Langmuir adsorption isotherm.

 

Keywords: Mild steel, heterocyclic anils, Langmuir adsorption isotherm, potentiodynamic polarization, impedance.

IPC Code: C23F 11/08

 

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp. 105-107

 

Effect of gamma radiation on solution viscosity of galactomannans: Influence of galactose : mannose ratio

 Roshan Issarani & B P Nagori*

 

Various seed galactomannans differ from each other in G:M ratios, molecular weight and fine structure, w.r.t. the distribution of galactose side groups on the main chain. In the present investigation, galactomannan samples of fenugreek, guar and locust bean having different G:M ratios of 1:1, 1:2 and 1:4 respectively, were exposed to different doses of gamma radiation. Dispersions of the resulting products were prepared and their viscosities were measured. A considerable fall in their viscosities was noted. The lower viscosity is obtained due to the production of lower molecular weight products, indicative of depoly­merization. It was observed that galactomannan having the highest galactose : mannose (G:M) ratio of 1:1 resisted depoly­merization the most in comparison to the galactomannan possessing the lowest G:M ratio of 1:4.

Keywords:   Depolymerization, gamma irradiation, galacto­mannas, locust bean, fenugreek, guar.

IPC Code: G05D 24/00

 

 

 

Indian Journal of Chemical Technology

Vol. 12, January 2005, pp. 108-122

 

Phosphorus-From discovery to commodity

Jaime Wisniak*

 

Phosphorus is nearly the most widely and evenly distributed element on the surface of the earth, and probably the most subdivided. From a laboratory curiosity in the seventeeth century, it became recognized as a fundamental element of life and a large chemical commodity, improving agriculture and industry like very few other discoveries by men have done.