A Closed-Loop Process from Microwave-Assisted Hydrothermal Degradation of Starch to Utilization of the Obtained Degradation Products as Starch Plasticizers
2014 (English)In: ACS Sustainable Chemistry and Engineering, ISSN 2168-0485, Vol. 2, no 9, 2172-2181 p.Article in journal (Refereed) Published
A green closed-loop water-based process for chemical recycling of starch was demonstrated. The process starts from microwave-assisted controllable starch degradation to functional chemicals and continues to utilization of the formed degradation products, glucose and levulinic acid (LA), as starch plasticizers. The degradation process and the effect of process parameters on the formed degradation products and residues were carefully fingerprinted by multiple techniques, e.g., NMR, ESI-MS, FTIR imaging, UV-vis, and SEM. The degradation process took place in three steps, proceeding from rupture of starch granules and oligosaccharide formation to further hydrolysis to glucose. Finally, at well-defined time point rapid degradation of glucose to LA and formic acid (FA) was initiated through a 5-hydroxymethyl furfural (5-HMF) intermediate. 5-HMF also participated in carbonization reactions leading to formation of solid carbon spheres. Through selection of processing parameters, LA could be produced in high yield with 9596 selectivity. The results demonstrated that microwave-assisted degradation of starch leads to well-defined controllable degradation products. These products are directly reusable as plasticizers for new starch products, which suggest great opportunities for biomass and starch recycling, opening the door toward potential industrial applications.
Place, publisher, year, edition, pages
2014. Vol. 2, no 9, 2172-2181 p.
Hydrothermal degradation, Levulinic acid, Microwave, Plasticizer, Recycling, Starch
IdentifiersURN: urn:nbn:se:kth:diva-152562DOI: 10.1021/sc500355wISI: 000341229100012ScopusID: 2-s2.0-84906880167OAI: oai:DiVA.org:kth-152562DiVA: diva2:750618
QC 201409292014-09-292014-09-292015-05-22Bibliographically approved