Synthesis of starch graft-copolymers via reactive extrusion: Process development and structural analysis. (1st January 2020)

• Record Type: Journal Article
• Authors: Siyamak, Samira; Laycock, Bronwyn; Luckman, Paul
• Is Part Of: Carbohydrate polymers. Volume 227(2020)
• Publication Date: 2020-01-01
• Subjects: Starch -- Acrylamide -- Reactive extrusion -- Graft copolymerization; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2019.115066
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: Graft-copolymers of starch and acrylamide monomer were prepared via reactive extrusion. Solvent-free graft copolymerization of starch at high solid concentration was completed within 5 min. An average monomer conversion of 80% and grafting efficiency of ˜74% was achieved. The starch type influenced the grafting reaction and properties of graft-copolymers. The starch-copolymers swelling behavior is comparable to that of synthetic hydrogels. Abstract: To promote the large-scale production of starch-based biomaterials, we developed a method of synthesis based on reactive extrusion that combines the benefits of continuous manufacturing with the use of green chemistry principles. This paper describes the grafting of four different types of starches with acrylamide monomers via free radical copolymerization using twin-screw extrusion technology. The elemental analysis confirmed the success of this method, with an average monomer conversion of 80% and grafting efficiency of ˜74% across all samples. The 13 C-NMR/ 1 H-NMR and ATR-FTIR analysis revealed that the type of starch substrate used strongly influenced the mechanism of the grafting reaction. Thermal analysis (TG/DTG-DSC) indicated that the graft-copolymers thermal stability was influenced by the amylose-amylopectin content ratio. Swelling tests suggested that cationic modification of the substrate is a promising approach to produce stimuli-responsive graft-copolymers via reactive extrusion. The proposed method has proved to be a viable alternative for the production of starch-copolymers.