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Network parameters and scaling behaviour of chemically crosslinked hydrogels of poly[( N , N ‐dimethylacrylamide)‐ co ‐(methyl methacrylate)]
Author(s) -
Liu Yan,
Mao Runsheng,
Huglin Malcolm B.,
Holmes Paul A.
Publication year - 1997
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.1997.021980617
Subject(s) - self healing hydrogels , copolymer , polymer chemistry , polymer , methacrylate , methyl methacrylate , chemical engineering , materials science , dynamic mechanical analysis , chemistry , composite material , engineering
Copolymerization of N,N ‐dimethylacrylamide (DMA) with methyl methacrylate in both the presence and absence of ethylene dimethacrylate (EDMA) was effected to very high conversion by γ‐irradiation. The resultant xerogels were swollen to equilibrium in water at five specific temperatures within the interval 280.2–338.2 K. The volume fractions of the polymer ϕ 2 in the hydrogels were determined from the measured dimensions, and compression‐strain measurements yielded the polymer‐water interaction parameter, the effective crosslinking densities, and Young's moduli Y . The observed dependence of these parameters on copolymer composition and content of EDMA is discussed. A scaling law of the form Y ∝ ϕ r 2is obeyed well by hydrogels of xerogels containing 80 wt.‐% DMA ( r = 2.37 ± 0.10) and moderately well by hydrogels of xerogels with only 50 wt.‐% DMA ( r = 2.54 ± 0.10).