Abstract
Three different brown acidic polymers with a significant proportion of unsaturated structures were prepared by acid-catalyzed dehydration of glucose. These nitrogen-free polymers were found comparable to humic substances in terms of their spectroscopic patterns (visible-UV, 1R and CPMAS 13C NMR), atomic ratios and molecular sizes and presented solubility properties similar to those of fulvic acids, humic acids or humins. The ‘building blocks’ of the above polymers were indirectly investigated by GC-MS applied to the free products in the glucose solution during successive condensation phases. The most abundant of the molecules formed under the conditions studied were 4-oxo-pentanoic acid, 5-(hydroxymethyl)-2-furancarboxaldehyde and 5-(methoxymethyl)-2-furancarboxaldehyde. Only in the case of the fulvic acid-like fraction, a predominant carbohydrate moiety in association with the polymer was detected. In the natural humic-type substances, the results obtained agree with the hypothetical presence of variable proportions of polymer structures derived from dehydration, breakdown and condensation of carbohydrate molecules that may be responsible for intense 13C resonances in spectral regions characteristic of the O-alkyl, aromatic and polymethylene type compounds.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
