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Influence of gel preparation concentration on statistical mechanics of poly(dialkylaminoethyl methacrylate) gels on the basis of scaling concept: Toward tunable elasticity and thermomechanical parameters
Author(s) -
Tanc Beril,
Orakdogen Nermin
Publication year - 2020
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.48350
Subject(s) - materials science , swelling , self healing hydrogels , scaling , exponent , polymer , methacrylate , elastic modulus , thermodynamics , elasticity (physics) , polymer chemistry , rubber elasticity , composite material , physics , mathematics , copolymer , linguistics , philosophy , geometry
In order to evaluate the scaling parameters of weakly cationic crosslinked network structures, poly(dialkylaminoethyl methacrylate)‐based hydrogels were synthesized via free‐radical crosslinking in aqueous solution varying systematically concentration of pregel solution. Based on the gel‐preparation concentration, variation in structural properties, effective crosslinking density, average molecular weight of polymer chains, and thermodynamic parameters from combined swelling and elasticity results were discussed using the scaling theory to predict various exponent identities. The concentration dependence of compressive elastic modulus as‐prepared state was described by a power‐law relationship G 0 ≈ν 2 0 m with the exponent of m = 3.55 indicating the importance of the trapped entanglements. Two structural characteristics, the network chain length N and the average molecular weight of polymer chains have inverse dependence on the gel‐preparation concentration in the matrix, while the compressive moduli and effective crosslinking density show completely direct dependence. Experimentally determined N values of PDMAEMA hydrogels first decrease with increasing ν 2 0 up to 0.2972 and the dependence of N on the gel‐preparation concentration gives the relation N ≈ X − 1ν 2 0 n with a scaling parameter n = −1.80, which coincides with the prediction of scaling theory. Acceptable agreement was found between the estimate of crosslink density fluctuations deduced from mechanical measurements and the results derived from independent swelling observations. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48350.