The changes of the cotton fibre microstructure as a result of annealing at temperatures from 20ºC to 300ºC were investigated by positron lifetime spectroscopy and differential scanning calorimetry. The aim of the paper was to examine the cotton cellulose thermal degradation process.
Incoherent quasielastic neutron scattering spectra were measured for nematic para-azoxyanisole (PAA) and para-azoxyphenetole (PAP) with the energy resolution of ca. 30 μ eV, at Dubna IBR-2 reactor. Data processing contained a careful background subtraction and the multiple scattering correction. The corrected spectra were subjected to a reorientational model fitting procedure. For PAA, a model of two convoluted reorientations - that of benzene rings coupled with the terminals and that of the whole molecule around the long molecular axis - gave a fairly good description of the quasielastic neutron scattering spectrum. For PAP, introducing a third motion - interconformational jumps in the ethoxy terminals - in addition to motions suggested for PAA, gave a good agreement with the measured quasielastic neutron scattering spectrum.
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.