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Title: Raman and infrared spectroscopy of simple- and poly-carbonates
Author: Wood, W. J.
Awarding Body: University College of Swansea
Current Institution: Swansea University
Date of Award: 1980
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The application of vibrational spectroscopy, especially laser Raman spectroscopy, to the polymer bisphenol-A polycarbonate has, until now, been limited to very elementary studies. This thesis describes detailed conformational and vibrational band assignment studies for a series of polycarbonate model compounds using both infrared and Raman spectroscopy. The results obtained are applied in the investigation of the polycarbonate. The model compounds used were bisphenol-A (2,2-bie (4-hydroxyphenyl)propane), together with the following organic carbonate molecules; diphenyl; methyl phenyl; methyl 4-isopropylphenyl; phenyl 4-isopropylphenyl and big 4-isopropylphenyl carbonates and the product of the reaction between the dichloroformate of bisphenol-A and 4-isopropylphenol, named 'Ibis-carbonate". The preparations and purifications of the organic carbonates are described in Chapter III and with the exceptions of diphenyl and methyl phenyl carbonates have not been reported previously. The carbonyl stretching absorption region in the infrared spectrum of the organic carbonates was studied by the solvent variation technique. Examination of the results shows clear indications of conformational equilibrium. Application of the dipolar association theory of Bellamy, Hallam and Williams comparing the carbonyl frequencies with those of the reference-acetophenone-in ten solvents, and dipole moment considerations (estimated from MINDO/3 calculations) both strongly suggest that the s-cis/scis conformer is preferred in non-polar media. The s-cis/s-traps form becomes increasingly d"t in more polar solvents. Solvent sensitivity in the 1350 to 1000rim region is also discussed in Chapter IV together with some low temperature H N.M.R. and C N.M.R. work. Brief infrared matrix isolation studies and band assignments of dimethyl, diethyl and methyl phenyl carbonates are described in Chapter V. Comprehensive vibrational band assignments (4000 - 50cm 1) for all the model compounds are discussed and tabulated in Chapter VI. The conformation and vibrational band assignments of bisphenol-A polycarbonate are discussed in Chapter VII. These results are applied to the changes known to occur in the Raman spectrum of the polymer when it is subject to mechanical loading.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available