Starch‐poly(acrylamide‐co‐2‐acrylamido‐2‐methylpropanesulfonic acid) graft copolymers prepared by reactive extrusion

Abstract

Graft copolymers of starch with acrylamide and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) were prepared by reactive extrusion in a twin-screw extruder. The weight ratio of total monomer to starch was fixed at 1 : 3, while the molar fraction of AMPS in the monomer feed ranged from 0 to 0.119. Monomer to polymer conversions were 85% or greater, with grafting efficiencies of 68% (highest AMPS content) to 85% (no AMPS). Absorbency in distilled water at pH 7 increased linearly with the mole fraction AMPS in the grafted polymer, while absorbencies in 0.9% NaCl were independent of AMPS content. When swollen in water/ ethanol mixtures, swelling decreased gradually with increasing ethanol volume fraction, followed by a large decrease over a narrow ethanol concentration. This behavior is similar to that observed for AMPS-acrylamide gels. The swelling properties suggest these graft copolymers may have applications as responsive materials.

Rheokinetics of graft copolymerization of acrylamide in concentrated starch and rheological behaviors and microstructures of reaction products

“…Based on these advantages, REX has been introduced to the chemical processing of bio-based polymeric materials to tailor their properties, which has been known as in-situ REX (Formela, Hejna, Haponiuk, & Tercjak, 2017). Recently, in-situ REX has been successfully applied into the chemical modification, compatibilization, and functionalization of the bio-based polymers, such as polylactide (PLA) (Ojijo & Ray, 2015;Yang, Cleńet, Xu, Odelius, & Hakkarainen, 2015), cellulose (Wei, McDonald, & Stark, 2015;Zhang, Li, Li, Gibril, & Yu, 2014), starch (Willett & Finkenstadt, 2015;Xu et al, 2017), lignin (Luo, Cao, & McDonald, 2016), and polycaprolactone (PCL) (Cayuela, Da Cruz-Boisson, Michel, Cassagnau, & Bounor-Legaré , 2016;Garcia-Garcia, Rayón, Carbonell-Verdu, Lopez-Martinez, & Balart, 2017). The main advantages of in-situ REX are the reduced costs due to a combination of polymer melting, physical blending of mixtures, and chemical reaction without purification of the final products.…”

“…In previous studies of the graft copolymerization of concentrated starch by REX (Carr, Kim, Yoon, & Stanley, 1992;Finkenstadt & Willett, 2005;Willett & Finkenstadt, 2003, 2006a, b, 2009Willett & Finkenstadt, 2015;Yoon, Carr, & Bagley, 1992), different reaction parameters such as the types of starch and monomer, moisture content, starch-to-monomer ratio, reaction temperature, content and type of the initiator, degree of filling, and extruder screw speed on the graft parameters of grafted starch have been fully investigated. Therefore, the effects of this wide range of reaction parameters were not the focus in this current work but we only investigated the parameters that would directly influence the reaction kinetics, microstructures, and rheological properties of the hydrogels, including the contents of the crosslinker and the initiator and the reaction temperature.…”

Functional starch-based hydrogels: renewable material solutions for wastewater and agriculture industries

“…The SWS-g-PAM high soluble content (72%), coupled with relatively high conversion (73%), indicates a high homopolymer content and formation of graft-copolymers with shorter starch fragments. The low graft content of these copolymers is also consistent with the larger soluble carbohydrate fraction (Willett & Finkenstadt, 2015). The average graft content for all graft-copolymers was 20% (±2%), with CTS-g-copolymer having…”

Construction and water absorption capacity of a 3D network‐structure starch‐g‐poly(sodium acrylate)/PVP Semi‐Interpenetrating‐Network superabsorbent resin

“…Thereinto, starch has triggered enormous research activities due to it bears a large amount of hydrophilic groups . Furthermore, starch grafted with some copolymers may significantly favor the water absorbency improvement of resins . Accordingly, it is frequently used as a basic skeleton to fabricate a superabsorbent resin (SAR).…”