Premium
Correlation of swelling and crosslinking density with the composition of the reacting mixture employed in radical crosslinking copolymerization
Author(s) -
Pacios Isabel E.,
Molina M. Jesús,
GómezAntón M. Rosa,
Piérola Inés F.
Publication year - 2006
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.25269
Subject(s) - copolymer , polymer chemistry , exponent , solvent , swelling , scaling , materials science , volume fraction , polymer , stoichiometry , aqueous solution , scaling law , thermodynamics , chemistry , physics , organic chemistry , composite material , mathematics , philosophy , linguistics , geometry
This article reports the scaling laws relating the synthesis conditions with the crosslinking density (ν e ) and swelling degree ( S ) of poly( N ‐vinylimidazole) hydrogels (PVI) prepared by radical crosslinking copolymerization in aqueous solution, with N,N ′‐methylene bisacrylamide (BA) as crosslinker. Multiple linear regression of ν e versus BA concentration ([BA]) and total comonomers concentration ( C T ) in double log scale render the scaling law ν e ∼ C T 0.81× [BA] 1.04 as comparable to that predicted by the model of polymer network with pendant vinyl groups (ν e ∼ C T × [BA]), and showing inverse dependence on C T to that expected, following from stoichiometry, for an ideal network (ν e ∼ 2[BA]/ C T ). S scales with ν e through a solvent‐dependent exponent ranging from −0.46 to −0.54, only slightly over the value predicted by the Flory–Rehner theory (−0.6) or the blob's model by de Gennes (−0.5 to −0.8). Finally, the scaling law of S with the composition of the reacting mixture is also solvent‐dependent and it seems to result not only from the dependence of ν e on C T and [BA] but also from that of v 2r , the polymer volume fraction in the reference state, and χ, the polymer–solvent interaction parameter. Models used seem to overestimate the contribution of entanglements to the effective crosslinking density of PVI. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 263–269, 2007