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Elucidation of the Chemical and Morphological Structure of Double‐Network (DN) Hydrogels by High‐Resolution Magic Angle Spinning (HRMAS) NMR Spectroscopy
Author(s) -
Shestakova Pavletta,
Willem Rudolph,
Vassileva Elena
Publication year - 2011
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201101334
Subject(s) - magic angle spinning , hydrogen bond , chemistry , covalent bond , self healing hydrogels , nuclear magnetic resonance spectroscopy , polymer chemistry , methylene , polymer , chemical shift , infrared spectroscopy , acrylamide , crystallography , molecule , stereochemistry , organic chemistry , monomer
1 H HRMAS NMR spectroscopy is applied to gain insight into the chemical and morphological structure of double‐network (DN) hydrogels, prepared from poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) (PAMPS) and poly(acrylamide) (PAAm). The method enables one to obtain detailed information at the molecular level about the formation of covalent bonds between the two polymer networks through non‐reacted double bonds of the cross‐linker N , N ′‐methylene bis(acrylamide) (MBAA). Evidence to the existence of strong hydrogen‐bond interactions based on the NH group of the PAMPS as a hydrogen‐bond donor and the CO group of the PAAm as a hydrogen‐bond acceptor is also provided. These findings clarify the origin of the toughening mechanism and the exceptionally strong mechanical properties of DN gels, further supported by microhardness data.