Harry A. Willis

Applications of Fourier Transform Raman spectroscopy in the synthetic polymer field

Abstract The application of FT Raman spectroscopy in the study of a wide range of polymer systems is discussed. The following have been included to give the reader an insight into the variety of areas which can successfully be studied using this important technique: the problem of crystallinity; nylons; poly(aryl ether ketone) and poly(aryl ether ether ketone); poly(aryl ether ether sulphone) and poly(aryl ether sulphone); epoxy resin curing; copolymers; copolymers of tetrafluoroethylene and hexafluoropropylene; polythioethers; and gels.

Some crystallization kinetics of isotactic polypropylene

Abstract Infra-red evidence is presented that the building of helices in the crystallization process from the glassy (or smectic) phase or from the melt are second order or zero-th order respectively. The observation coupled with data from density and X-ray diffraction measurements is interpreted in molecular structural terms.

The Raman spectra of some aromatic nitro compounds

Abstract The paper provides a re-appraisal of the analytical value of Raman spectroscopy in the investigation of aromatic nitro compounds. Correlations are found between the frequencies of the NO vibrations and the electron-donating and -withdrawing effects of substituents on the phenyl rings. Further, relations are discussed between the highest-frequency CH stretching mode and the electron density and number of nitro groups. The paper contains a large number of spectra of typical aromatic nitro compounds.

Fourier transform Raman spectroscopy in the analysis of polypeptides

The use of near-infrared Fourier transform Raman spectroscopy in the analysis of polypeptides is critically reviewed. A range of peptides and polypeptides are discussed and show promising results in the pure crystalline form. However, in aqueous solution analogous to in vitro conditions the results are disappointing and further developments in Fourier transform Raman techniques are required before the technique, applicable to these compounds, can be successful.

Raman spectroscopy of flowing poly(ethylene terephthalate) melts

Abstract Studies have been made of the Raman spectrum of a poly(ethylene terephthalate) melt being extruded through a glass die. The effects observed in the spectrum are interpreted in terms of changes in molecular shape which vary with shear rate and melt temperature.

The vibrational analysis of polyperdeuteroethylene

Abstract The i.r. and Raman spectra of polyperdeuteroethylene (recorded at room temperature and at 77 K) are presented and discussed. The presence of lattice modes and a longitudinal acoustic mode were observed. The spectrum is assigned to the fundamental modes of vibration.