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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Characterisation of complex polymer mixtures

Al-Harbi, Nasser Munawir D. January 2011 (has links)
The polymer of intrinsic microporosity PIM-1 was synthesized following various procedures: (i) from fluoro-monomer by the conventional method, (ii) from fluoro-monomer by a high temperature, high shear mixing method and (iii) from chloro-monomer. For a more complete understanding of the structure of the resultant products of a series of polymerizations under different reaction conditions, a multi-detector gel permeation chromatography (GPC) method was established and validated. A procedure for fractionating PIM-1 using chloroform methanol solvent mixtures was established and validated. A combination of multi-detector GPC and matrix-assisted laser desorption/ionization-time of flight (MALDI-ToF) masss pectrometry was used for the determination of molar mass distribution and to identify structural differences between fractions and between the products from different synthetic procedures. High molar mass samples tended to have broader molar mass distributions. Both Mark-Houwink plots and hydrodynamic volume plots showed deviation from linearity at Mw= 200000 g mol-1, which was attributed to branching. A low cost route for the preparation of PIM-1 from chloro-monomer was successfully established, though samples prepared by this route had broader polydispersities than those prepared from fluoro-monomers. It was found that stable flexible membranes were formed from samples with Mw > 83000 g mol -1. In addition, a comparison of two analytical methods for extraction and determination of additives in HDPE, LLDPE and PP polymers of interest to Saudi Basic Industries Corporation was performed. A comparison of dissolution with ultrasonic assisted extraction methods for the determination of anti-oxidant additives in polyolefins was performed. Ultrasound assisted extraction methods were found to be superior for HDPE and LLDPE, where conventional dissolution was preferred for PP.
2

The influence of acid and direct azo dyes and their intermediates on the degradation of wool keratin : the characterisation by yarn strength measurements of the degradation of wool under conditions relevant to dyeing and of the keratin degradation products, by fractionation, electrophoresis and amino acid analysis

McComish, John January 1981 (has links)
The degradation of wool keratin under conditions relevant to those of wool dyeing was investigated using the techniques of gel permeation chromatography (GPC), ion exchange gel chromatography, and amino acid analysis. Physical testing of the treated and untreated wool was also carried out to determine the physical changes occurring, parameters used being percentage elongation at the break, and the breaking strain of the fibre. Samples of wool keratin were immersed in various aqueous solutions at 1000C for 24 hours and the filtered, aqueous, oxidised extracts were analysed* The solutions used varied only in the dye, or dye intermediate present in the treatment solution. All treatment baths contained 10% owf 1.02 x 10 -2 MSulphuric VI acid; 10%owf 7.04x 10 -3 MSodium sulphate VI ; A 100 :1 liquor ratio was used in each case. Some of the dye intermediates showed a marked catalytic effect, particularly in their effect on breaking strain, a decrease of 40% in some cases. The GPC profiles of the extracted proteins were examined in detail and compared against previous workers' results. An explanation of the behaviour of the dyes and intermediates was proposed. The amino acid composition data of the extracted and fractionated proteins were compared against various morphological components extracted by other workers, as was the total gelatin obtained from each treatment.
3

The influence of acid and direct azo dyes and their intermediates on the degradation of wool keratin. The characterisation by yarn strength measurements of the degradation of wool under conditions relevant to dyeing and of the keratin degradation products, by fractionation, electrophoresis and amino acid analysis.

McComish, John January 1981 (has links)
The degradation of wool keratin under conditions relevant to those of wool dyeing was investigated using the techniques of gel permeation chromatography (GPC), ion exchange gel chromatography, and amino acid analysis. Physical testing of the treated and untreated wool was also carried out to determine the physical changes occurring, parameters used being percentage elongation at the break, and the breaking strain of the fibre. Samples of wool keratin were immersed in various aqueous solutions at 1000C for 24 hours and the filtered, aqueous, oxidised extracts were analysed* The solutions used varied only in the dye, or dye intermediate present in the treatment solution. All treatment baths contained 10% owf 1.02 x 10 -2 MSulphuric VI acid; 10%owf 7.04x 10 -3 MSodium sulphate VI ; A 100 :1 liquor ratio was used in each case. Some of the dye intermediates showed a marked catalytic effect, particularly in their effect on breaking strain, a decrease of 40% in some cases. The GPC profiles of the extracted proteins were examined in detail and compared against previous workers' results. An explanation of the behaviour of the dyes and intermediates was proposed. The amino acid composition data of the extracted and fractionated proteins were compared against various morphological components extracted by other workers, as was the total gelatin obtained from each treatment. / Science Research Council

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