Rheology and microstructure of solutions of the microbial polysaccharide from Pseudomonas elodea

✍ Scribed by Vincent Carroll; Graham R. Chilvers; David Franklin; Mervyn J. Miles; Victor J. Morris; Steven G. Ring

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 701 KB
• Volume: 114
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(83)88185-3

✦ Synopsis

AEBTRACT

Rheological studies of solutions and gels of the microbial polysaccharide from the organism Pseudomonas elodea have been combined with X-ray diffraction studies of fibres and pulsed electric-bir~fring~n~e studies of dilute solutions, to investigate the conformation and interaction of the polymer molecules. Rheoiogical data are suggestive of a locally rigid conformation for the biopolymer in solution. X-Ray diffraction studies suggest that the molecules adopt a three-fold helical structure. O-Acetyl substituents have been shown to inhibit the packing of these helices into crystalline domains. Studies of pulsed electric-birefringenc~ suggest an extended, kinetically rigid structure in solution. Dissolving the polysa~charide in dimethyl sulphoxide inhibits the gelation and shear-thinning characteristics of aqueous solutions. Comparative studies of electric birefringence of solutions in water and dimethyl sulphoxide suggest that the differences in rheological properties may result from a change in molecular conformation.