caa a22 4500 463229754 CHVBK 20180405153238.0 cr unu---uuuuu 170326e20070701xx s 000 0 eng 10.1007/s10853-006-0989-4 doi (NATIONALLICENCE)springer-10.1007/s10853-006-0989-4 On the solid-state ageing behaviour of the polysaccharide, guar gum [Elektronische Daten] [L. Barré, A. Vaughan, S. Sutton] Dilute solution viscometry was used to explore the effect of solid-state ageing on the interactions that occur between guar gum and water. The resulting data set, derived from nearly 700 independent experiments, led to a value for the Flory-Huggins interaction parameter, χ, of 0.56±0.12. This value, which appeared independent of ageing, is in good agreement with the majority of published data. The effect of ageing on molar mass was also explored, using Mark-Houwink-Sakurada (MHS) theory. Absolute molar mass values were found to depend sensitively on the choice of MHS constants, but the effect of ageing was unequivocal; under all conditions, it resulted in a pronounced decrease in molar mass. In concert, these results strongly suggest that, in guar, solid-state ageing reactions are largely associated with scission of the molecular backbone. This hypothesis was then tested by infra-red and Raman spectroscopy. Although infra-red spectroscopy did reveal some subtle differences between the spectra of guar and locust bean gum (LBG), a related polysaccharides with a different galactose:mannose ratio, no equivalent effects were seen in aged guar. However, clear differences between the Raman spectra of guar and LBG were seen, demonstrating that the technique is well capable of revealing changes in galactose:mannose ratios. Examination of aged guar samples revealed no comparable effects, reinforcing the notion that, in this polysaccharide, chain scission reactions dominate such that solid-state ageing does not lead to changes in the nature of its interaction with water. Springer Science+Business Media, LLC, 2007 Barré L. School of Electronics and Computer Science, University of Southampton, SO17 1BJ, Highfield, Southampton, UK aut Vaughan A. School of Electronics and Computer Science, University of Southampton, SO17 1BJ, Highfield, Southampton, UK aut Sutton S. National Grid, NGT House, Warwick Technology Park, Gallows Hill, CV34 6DA, Warwick, Coventry, UK aut Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/14(2007-07-01), 5497-5507 0022-2461 42:14<5497 2007 42 10853 https://doi.org/10.1007/s10853-006-0989-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-006-0989-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Barré L. School of Electronics and Computer Science, University of Southampton, SO17 1BJ, Highfield, Southampton, UK aut NATIONALLICENCE 700 1- Vaughan A. School of Electronics and Computer Science, University of Southampton, SO17 1BJ, Highfield, Southampton, UK aut NATIONALLICENCE 700 1- Sutton S. National Grid, NGT House, Warwick Technology Park, Gallows Hill, CV34 6DA, Warwick, Coventry, UK aut NATIONALLICENCE 773 0- Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/14(2007-07-01), 5497-5507 0022-2461 42:14<5497 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer