Study of polymer–polymer complexes and blends of poly(N-isopropylacrylamide) with poly(carboxylic acid). 2. Poly(acrylic acid) and poly(methacrylic acid) partially neutralized

Garay, M. T.; Alava, Cristina; Rodrı́guez, M.

doi:10.1016/s0032-3861(99)00765-x

Cited by 59 publications

(43 citation statements)

References 32 publications

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“…In the case of the systems used in our work, the presence of isopropyl side groups in PNIPAAm and methyl groups in PMAA may contribute significantly to complex stabilization via hydrophobic forces. [14] In a previous study, [15] two different crosslinked PNIPAAm and PMAA homopolymers, as well as their copolymers and interpenetrating networks, were characterized in the swollen state by means of 1 H and 13 C NMR spectroscopy. 1 H MAS spectra revealed that gels with a high MAA content have very restricted molecular mobility even in the swollen state, as reflected by the broad lineshapes of the 1 H resonances.…”

Section: Introductionmentioning

confidence: 99%

Advanced ¹H Solid‐State NMR Spectroscopy on Hydrogels, 2

Díez-Peña

Quijada‐Garrido

Barrales‐Rienda

et al. 2004

Macro Chemistry & Physics

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Summary: Advanced 1H solid‐state NMR methods are applied for studying the hydrogen bond formation occurring in polymer hydrogels based on N‐isopropylacrylamide (NIPAAm) and methacrylic acid (MAA). For P(NIPAAm‐co‐MAA) copolymers collapsed at low pH, two populations of water can be distinguished in 1H magic‐angle spinning (MAS) NMR spectra, one of which is probably situated near stable hydrogen‐bonded regions, while the other behaves similarly to free water. The pH‐induced polymer collapse can be followed in detail using 2D 1H‐1H double quantum (DQ) MAS NMR experiments on dried samples. For collapsed copolymers as well as interpenetrating polymer networks, the appearance of characteristic signals shows that hydrogen bonding takes place between NIPAAm and MMA monomers. The temperature dependence of the DQ spectra indicates that acid‐amide hydrogen bonds formed between both comonomers are more stable than the acid‐acid hydrogen bonds formed among MAA moieties alone. Correspondingly, by analyzing 1H‐1H DQ sideband patterns, a relatively short distance of 270 pm is found for the NIPAAm‐MMA hydrogen bond. Finally, the pH dependence of the DQ spectra demonstrates that hydrogen bonding phenomena are directly related to the polymer collapse. magnified image

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Section: Introductionmentioning

confidence: 99%

Advanced ¹H Solid‐State NMR Spectroscopy on Hydrogels, 2

Díez-Peña

Quijada‐Garrido

Barrales‐Rienda

et al. 2004

Macro Chemistry & Physics

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“…Adversely, where there is strong polymer-polymer hydrogen bonding causing gel collapse and preventing swelling, increasing temperature breaks the associative bonds effectively increasing the solvent quality to a similar effect as with dipole interactions. Interactions between carboxylic acid and amide functional groups can yield these strong polymer-polymer hydrogen bonds [26,46]. This was shown by Garay et al through potentiometry in protic solvent.…”

Section: Hydrogen Bondingmentioning

confidence: 88%

Thermo-Responsive Hydrogels for Stimuli-Responsive Membranes

Mah

Ghosh

2013

Processes

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Abstract:Composite membranes with stimuli-responsive properties can be made by coating a thermo-responsive hydrogel onto a micro-or macroporous support. These hydrogels undergo a temperature induced volume-phase transition, which contributes towards the composite membrane's stimuli-responsive properties. This paper reviews research done on complimentary forms of temperature responsive "thermophilic" hydrogels, those exhibiting positive volume-phase transitions in aqueous solvent. The influences of intermolecular forces on the mechanism of phase-transition are discussed along with case examples of typical thermophilic hydrogels.

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“…Around 250°C, the polymer shows the first relevant and sharp mass loss. This event is due to a degradation of the PAA fractions of the polymer corresponding to the anhydride formation, followed by its decomposition [27]. Finally, the greatest weight loss (approximately 40% of the total mass) from 360 to is close to 450°C is due to main chain degradation events [28].…”

Section: Sap5 Characterizationmentioning

confidence: 99%

Synthesis and characterization of high performance superabsorbent hydrogels using bis[2-(methacryloyloxy)ethyl] phosphate as crosslinker

Gonçalves¹,

Fonseca²,

Fabela³

et al. 2016

Express Polym. Lett.

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Abstract. Various superabsorbent polymers (SAPs) were synthesized by free radical copolymerization at 70°C using acrylic acid (AA), potassium acrylate (KA), N-isopropyl acrylamide (NIPAM) and sulfopropyl methacrylate potassium salt (SPM) as monomers, bis [2-(methacryloyloxy)ethyl] phosphate (BMEP) as crosslinker and potassium persulfate (KPS) as initiator. The optimization of the synthesis led to the preparation of a SAP with very high water absorption ability, with a maximum swelling of 2618 g water/g dry hydrogel. The most promising SAP was fully characterized and the absorption capacities were studied at different pH and ionic strengths. When this SAP was mixed with soil, the mixture was able to lose water more slowly. Also, this material revealed high loading capacity and showed good releasing profiles using urea as model fertilizer. Due to these advantageous properties, the synthesized SAP can be used in agricultural applications.

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Study of polymer–polymer complexes and blends of poly(N-isopropylacrylamide) with poly(carboxylic acid). 2. Poly(acrylic acid) and poly(methacrylic acid) partially neutralized

Cited by 59 publications

References 32 publications

Advanced ¹H Solid‐State NMR Spectroscopy on Hydrogels, 2

Advanced ¹H Solid‐State NMR Spectroscopy on Hydrogels, 2

Thermo-Responsive Hydrogels for Stimuli-Responsive Membranes

Synthesis and characterization of high performance superabsorbent hydrogels using bis[2-(methacryloyloxy)ethyl] phosphate as crosslinker

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Study of polymer–polymer complexes and blends of poly(N-isopropylacrylamide) with poly(carboxylic acid). 2. Poly(acrylic acid) and poly(methacrylic acid) partially neutralized

Cited by 59 publications

References 32 publications

Advanced 1H Solid‐State NMR Spectroscopy on Hydrogels, 2

Advanced 1H Solid‐State NMR Spectroscopy on Hydrogels, 2

Thermo-Responsive Hydrogels for Stimuli-Responsive Membranes

Synthesis and characterization of high performance superabsorbent hydrogels using bis[2-(methacryloyloxy)ethyl] phosphate as crosslinker

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Product

Resources

About

Advanced ¹H Solid‐State NMR Spectroscopy on Hydrogels, 2

Advanced ¹H Solid‐State NMR Spectroscopy on Hydrogels, 2