Synthesis and characterization of a new type of levan-graft-polystyrene copolymer

Branka Kekez; Gordana Gojgić-Cvijović; Dragica Jakovljević; Vladimir Pavlović; Vladimir Beškoski; Aleksandar Popović; Miroslav M Vrvić; Vladimir Nikolić

doi:10.1016/j.carbpol.2016.08.001

Synthesis and characterization of a new type of levan-graft-polystyrene copolymer

Carbohydr Polym. 2016 Dec 10:154:20-9. doi: 10.1016/j.carbpol.2016.08.001. Epub 2016 Aug 2.

Authors

Branka Kekez¹, Gordana Gojgić-Cvijović², Dragica Jakovljević³, Vladimir Pavlović⁴, Vladimir Beškoski⁵, Aleksandar Popović⁶, Miroslav M Vrvić⁷, Vladimir Nikolić⁸

Affiliations

¹ Faculty of Chemistry, University of Belgrade, Studentski Trg 12-16, Belgrade 11000, Serbia. Electronic address: brankakekez@chem.bg.ac.rs.
² Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoševa 12, 11000 Belgrade, Serbia. Electronic address: ggojgic@chem.bg.ac.rs.
³ Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoševa 12, 11000 Belgrade, Serbia. Electronic address: djakovlj@chem.bg.ac.rs.
⁴ Faculty of Agriculture, University of Belgrade, Nemanjina 6, Belgrade 11080, Serbia. Electronic address: vlaver@agrif.bg.ac.rs.
⁵ Faculty of Chemistry, University of Belgrade, Studentski Trg 12-16, Belgrade 11000, Serbia. Electronic address: vbeskoski@chem.bg.ac.rs.
⁶ Faculty of Chemistry, University of Belgrade, Studentski Trg 12-16, Belgrade 11000, Serbia. Electronic address: apopovic@chem.bg.ac.rs.
⁷ Faculty of Chemistry, University of Belgrade, Studentski Trg 12-16, Belgrade 11000, Serbia. Electronic address: mmvrvic@chem.bg.ac.rs.
⁸ Innovation Center, Faculty of Chemistry, University of Belgrade, Studentski Trg 12-16, Belgrade 11000, Serbia. Electronic address: nikolicv@chem.bg.ac.rs.

PMID: 27577892
DOI: 10.1016/j.carbpol.2016.08.001

Abstract

Novel macromolecular graft copolymers were synthesized by reaction of the hydroxyl groups of the microbial polysaccharide levan, produced using Bacillus licheniformis, with polystyrene (Lev-g-PS). Synthesis was performed by the free radical reaction using potassium persulfate (PPS) as initiator. The prepared copolymer was characterized by FTIR, SEM, TG/DTA, XRD and (13)C NMR. The influence of the different conditions (reaction temperature, air or nitrogen atmosphere, reaction time, type of amines and ascorbic acid (AA) concentration) on the grafting reaction was investigated. Results showed that maximum percentage of grafting (58.1%) was achieved at a reaction temperature 70°C, in a nitrogen atmosphere and using dimethylethanolamine (DMEA) as the amine activator. On the basis of the obtained results, the likely reaction mechanism was proposed. Synthesized copolymers have better thermal stability in comparison with their initial components. Copolymers such as Lev-g-PS could potentially have many applications, such as compatibilizers and material for membranes.

Keywords: Dimethylethanolamine (PubChem CID: 7902); Graft copolymer; Levan; Levan (PubChem CID: 5254051); Microbial polysaccharide; Potassium persulfate (PubChem CID: 24412); Styrene; Styrene (PubChem CID: 7501).