Abstract
To characterize the effectiveness of water as a diluent in depressing the melting temperature of amylose crystals, maltooligomer/water interactions were probed, as a function of composition, by calorimetry and vapour sorption measurements. These studies, in part analysed using the Flory-Huggins theory of polymer solutions, showed that although there is a strong energetic interaction between water and the oligomeric chain, this is balanced by an opposing, first neighbour entropic contribution. At room temperature, water was characterized as a poor solvent for the amylose chain. The dissolution in water of the B-type crystalline polymorph of amylose, crystallized from fractions of limited polydispersity, ranging in chain length from 12 to 55 residues, was examined by scanning calorimetry. With increasing chain length in this range, the dissolution temperature, at a volume fraction of water of 0.8, increased from 57 to 119 °C. The extrapolated dissolution temperature for the high molecular weight polymer at this water content was 147 °C.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.