Götz T, Schädel N, Petri N, Kirchhof M, Bilitewski U, Tovar GEM, Laschat S, Southan A. Triazole-based cross-linkers in radical polymerization processes: tuning mechanical properties of poly(acrylamide) and poly(
N,N-dimethylacrylamide) hydrogels.
RSC Adv 2018;
8:34743-34753. [PMID:
35548633 PMCID:
PMC9086908 DOI:
10.1039/c8ra07145d]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 09/07/2018] [Indexed: 11/21/2022] Open
Abstract
Triazole-based cross-linkers with different spacer lengths and different functional end groups (acrylamides, methacrylamides, maleimides and vinylsulfonamides) were synthesized, investigated for cytotoxic and antibacterial activity, and incorporated into poly(acrylamide) (PAAm) and poly(N,N-dimethylacrylamide) (PDMAAm) hydrogels by free-radical polymerization. Hydrogels prepared with different cross-linkers and cross-linker contents between 0.2% and 1.0% were compared by gel yields, equilibrium degrees of swelling (S) and storage moduli (G'). Generally with increasing cross-linker content, G' values of the hydrogels increased, while S values decreased. The different polymerizable cross-linker end groups resulted in a decrease of G' in the following order for cross-linkers with C4 spacers: acrylamide > maleimide > methacrylamide > vinylsulfonamide. Longer cross-linker alkyl spacer lengths caused an increase in G' and a decrease in S. Independent of the cross-linker used, a universal correlation between G' and equilibrium polymer volume fraction ϕ was found. For PAAm hydrogels, G' ranged between 4 kPa and 23 kPa and ϕ between 0.07 and 0.14. For PDMAAm hydrogels, G' ranged between 0.1 kPa and 4.9 kPa and ϕ between 0.02 and 0.06. The collected data were used to establish an empirical model to predict G' depending on ϕ. G' of PAAm and PDMAAm hydrogels is given by G' = 4034 kPa ϕ 2.66 and G' = 4297 kPa ϕ 2.46, respectively.
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