Influence of crosslinker amount on the microstructure and properties of starch-based superabsorbent polymers by one-step preparation at high starch concentration

Qiao, Dongling; Tu, Wenyao; Wang, Zhong; Yu, Long; Zhang, Binjia; Bao, Xianyang; Jiang, Fatang; Lin, Qinlu

Abstract

This work concerns how crosslinker amount (N, N′-methylene-bisacrylamide) affects the microstructural, absorbent and rheological features of one-step prepared starch-based superabsorbent polymers at a high starch concentration (0.27:1 w/w starch-water). The increased crosslinker amount evidently altered the microstructure and the absorbent and rheological features. Then, the variations in starch-based superabsorbent polymer properties were discussed from a microstructure viewpoint. Particularly, the higher crosslinker quantity rose the crosslinking density and the ratio (GR) of grafted anhydroglucose unit on starch backbone (from 27% to 52%), but short the average polyacrylamide (PAM) chain length (LPAM). These structural features suppressed the chain stretch within starch-based superabsorbent polymer fractal gels (confirmed by smaller Rg value) and promoted the formation of smaller chain networks, thus weakening the water absorption to the starch-based superabsorbent polymer chain networks. Also, the increased GR and reduced LPAM, with lowered chain extension and elevated crosslinking density, probably decreased the flexibility and mobility of chain segments in starch-based superabsorbent polymer gel matrixes. This caused the enhanced robustness and storage modulus of the gels with reduced chain energy dissipation ability.

Citation

Qiao, D., Tu, W., Wang, Z., Yu, L., Zhang, B., Bao, X., …Lin, Q. (2019). Influence of crosslinker amount on the microstructure and properties of starch-based superabsorbent polymers by one-step preparation at high starch concentration. International Journal of Biological Macromolecules, 129, 679-685. https://doi.org/10.1016/j.ijbiomac.2019.02.019

• Journal Article Type: Article
• Acceptance Date: Feb 3, 2019
• Online Publication Date: Feb 7, 2019
• Publication Date: May 15, 2019
• Deposit Date: Nov 9, 2020
• Publicly Available Date: Nov 10, 2020
• Journal: International Journal of Biological Macromolecules
• Print ISSN: 0141-8130
• Electronic ISSN: 1879-0003
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 129
• Pages: 679-685
• DOI: https://doi.org/10.1016/j.ijbiomac.2019.02.019
• Keywords: Biochemistry; Molecular Biology; Structural Biology; General Medicine
• Public URL: https://nottingham-repository.worktribe.com/output/5031234
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0141813018369691
• Additional Information: This article is maintained by: Elsevier; Article Title: Influence of crosslinker amount on the microstructure and properties of starch-based superabsorbent polymers by one-step preparation at high starch concentration; Journal Title: International Journal of Biological Macromolecules; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.ijbiomac.2019.02.019; Content Type: article; Copyright: © 2019 Elsevier B.V. All rights reserved.