Document Detail


Influence of anomeric configuration on mechanochemical degradation of polysaccharides: cellulose versus amylose.
MedLine Citation:
PMID:  18030997     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Cellulose and amylose are (1-->4)-linked polysaccharides that are used extensively in the textiles, paper, and food and feed industries and are finding increasing use as alternative fuels and so forth. At the molecular level, cellulose and amylose differ only in their anomeric configuration: beta in cellulose, alpha in amylose. During processing and end use, these polymers experience a variety of mechanochemical stresses, many through contact with transient elongational flow fields. Here, we subject solutions of both polysaccharides to extended periods of ultrasonic irradiation, as the cavitational bubble collapse characteristic of ultrasound experiments creates flow fields strictly analogous to those encountered in other transient elongational flow scenarios. With the use of multidetector size-exclusion chromatography, the effects of anomeric configuration on both the limiting molar mass, beyond which polymers do not degrade in transient elongation flow ( M lim), and the rate of degradation have been isolated in these (1-->4)-linked polysaccharides. This effect was found to be pronounced; for example, M lim (cellulose) = 5( M lim (amylose)). Also, while extensive change was observed in molar mass averages, distribution, polydispersity, and size of the analytes during degradation, their structure was found to remain invariant. A modified "path theory" of transient elongational flow degradation was proposed, with the persistence length identified as a parameter which embodies the minimum continuous path length and flexibility requirements of the theory.
Authors:
André M Striegel
Related Documents :
22909137 - Reference values of hematology, chemistry, electrolytes, blood gas, coagulation time, a...
560937 - Lipid hemodialysis versus charcoal hemoperfusion in imipramine poisoning.
24237157 - In vitro evaluation of a novel autologous aortic valve (biovalve) with a pulsatile circ...
22959107 - Relative changes in transcranial doppler velocities are inferior to absolute thresholds...
20416817 - Composition and color stability of carbon monoxide treated dried porcine blood.
2611197 - Fluorescein angiographic findings in three patients with long-term intravitreal liquid ...
Publication Detail:
Type:  Comparative Study; Journal Article     Date:  2007-11-20
Journal Detail:
Title:  Biomacromolecules     Volume:  8     ISSN:  1526-4602     ISO Abbreviation:  Biomacromolecules     Publication Date:  2007 Dec 
Date Detail:
Created Date:  2007-12-11     Completed Date:  2008-02-28     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100892849     Medline TA:  Biomacromolecules     Country:  United States    
Other Details:
Languages:  eng     Pagination:  3944-9     Citation Subset:  IM    
Affiliation:
Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, USA. striegel@chem.fsu.edu
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Amylose / chemistry*,  metabolism
Cellulose / chemistry*,  metabolism
Molecular Conformation
Polysaccharides / chemistry*,  metabolism
Chemical
Reg. No./Substance:
0/Polysaccharides; 9004-34-6/Cellulose; 9005-82-7/Amylose

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Metallo-phthalocyanine near-IR fluorophores: oligonucleotide conjugates and their applications in PC...
Next Document:  A high strength nanocomposite based on microcrystalline cellulose and polyurethane.