Complexation of poly(ethylene oxide) with poly(acrylic acid-co-hydroxyethyl methacrylate)s

Abstract

Abstract-Random acrylic acid/hydroxyethyl methacrylate (AA/HEMA) copolymers were synthesized to study the influence of non-ionic (HEMA) structure defects introduced in poly(acrylic acid) on the complex formation with PEO (fiW 23200) at pH 3-3.5 in aqueous solution. Complex formation as studied with potentiometric titration (concentration 0.01-0.03 M monomer residues) was increasingly impeded when the molar ratio of HEMA to AA units in the polymers increased. Copolymers of AA and HEMA with molar ratios 30: 1, 10 : 1 and 3 : 1 were used in this study. It was shown that in the copolymers the number of carboxylic acid groups taking part in complexation decreased with increasing amounts of HEMA in the copolymer. However, with increasing amounts of structure defects the amount of PEO per AA residue (at equilibrium complexation) increased, suggesting less efficient packing of PEO on the acrylic copolymer chain. Copyright 0 1996

Progress in the development of interpenetrating polymer network hydrogels

“…This is supportive of the concept we have proposed that hydrogen bonding between the PAA and PEG networks serves to reinforce the network and prevent cracks from propagating, leading to an IPN with increased resistance to fracture at high strains. This is consistent with the work of Krupers et al 32 who first showed in solutions that the nature of the AA-based copolymer is important for complexation with PEG.…”

“…Since complexation in these systems occurs between hydrophilic acid groups of the PAA or PMAA with the oxygens on the PEG chain, the resultant interpolymer complex is more hydrophobic than the individual polymers alone. 29 The complexation between PEG and PAA has been verified experimentally by viscometry and potentiometry experiments, 13,14,[30][31][32] excimer fluorescence, 33,34 photon correlation spectroscopy, 35 solution microcalorimetry, 36 differential scanning calorimetry, Fourier-transform infrared spectroscopy, 37 and other fluorescence-based techniques. 31,38 The results shown in Fig.…”

Synthetic Hydrophilic Materials with Tunable Strength and a Range of Hydrophobic Interactions

“…If they are too large, the PEG molecules will completely cover the domains at any environmental conditions (see Supporting Information for details). In addition, PEG chains with degree of polymerization below 180 do not form complexes with PAA at the lower pH values (pH 3–3.5) 33…”

Molecular interactions in poly(methacrylic acid)/poly(N‐isopropyl acrylamide) interpenetrating polymer networks

“…Copolymers and IPNs of two polymers that form hydrogen‐bonded complexes have been extensively studied 1, 19–27. These polymer complexes involve carboxyl groups (proton donors) and ether or amide groups (proton acceptors).…”