NOPR Collection:

The History of Iodine From Discovery to Commodity

Thu, 01 Nov 2001 00:00:00 GMT

Title: The History of Iodine From Discovery to Commodity Authors: Wisniak, Jaime Abstract: 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. Page(s): 518-526

Synthesis and characterization of new polycrown ether (schiff base)

Thu, 01 Nov 2001 00:00:00 GMT

Title: Synthesis and characterization of new polycrown ether (schiff base) Authors: Dutta, Pradip Kumar Abstract: 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. Page(s): 515-517

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

Thu, 01 Nov 2001 00:00:00 GMT

Title: Phase transfer catalysed polymerisation of butyl methacrylate using potassium peroxydisulphate as initiator—A kinetic study Authors: Umapathy, M J; Mohan, D Abstract: The kinetics of phase transfer catalysed free radical polymerisation of butyl methacrylate using potassium peroxydisulphate as water soluble initiator and propiophenonebenzyl- dimethylammonium 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 (R_p) is independent of ionic strength and pH. However, an increase in the polarity of solvent and volume fraction of aqueous phase slightly increases the R_p value. Based on the results obtained, a mechanism has been proposed for the polymerisation reaction. Page(s): 510-514

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

Thu, 01 Nov 2001 00:00:00 GMT

Title: Design of commercial batch fractionating columns for separation of α- & β-pinenes from turpentine oil by the simple method developed Authors: Sama, J K; Bandopadhyay, P Abstract: A commercial batch fractionating column, for separating α- & β-pinenes from a multicomponent mixture, such as turpentine 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. Page(s): 500-509