Vesicular Ionic Aggregates in Poly(styrene-<i>r</i><i>an</i>-methacrylic acid) Ionomers Neutralized with Cs

Kirkmeyer, Brian P.; Taubert, Andreas; Kim, Joon‐Seop; Winey, Karen I.

doi:10.1021/ma011482h

Cited by 37 publications

(40 citation statements)

References 12 publications

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“…41,49 While the results are in qualitative agreement and quantitative consensus with the trends reported previously, 42,43,[50][51][52] we are aware that the simple model we employ describes the material only very coarsely, and that a large variety of morphologies, including spherical aggregates, string-like structures and percolated networks 50 has previously been reported for ionomeric polymers with a moderate to high ion fraction. Consequently, as the ionomers exhibit a similar composition (w ion B 4.5%), the volume occupied by each cation is either smaller, or the ions show a closer packing in the ion-rich phase.…”

Section: Structural Characterizationsupporting

confidence: 88%

Self-healing dynamic bond-based rubbers: understanding the mechanisms in ionomeric elastomer model systems

Hohlbein

Shaaban

Brás

et al. 2015

Phys. Chem. Chem. Phys.

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While it is traditionally accepted that the chain interactions responsible for the elastic response in an elastomeric network are ideally permanent and instantaneously active, the ongoing investigation of self-healing materials reveals that the introduction of self-healing properties into elastomers requires high mechanical integrity under dynamic load conditions, while on long timescales (or at extended temperatures), the chain and bond dynamics must allow for an intrinsic repair of micro cracks occurring during operation and aging. Based on an acrylate-based amorphous ionomer model system with pendant carboxylate groups allowing the systematic variation of the composition and the nature of the counter ion, we demonstrate the interrelation between the morphological, thermal, and mechanical properties, and identify the prerequisites and tools for property adjustment and optimization of self-healing efficiency. While the ion fraction is directly related to the effective network density and elastic performance, the crossover frequency between viscous and elastic behavior is influenced by the nature of the counter ion. In order to achieve reliable elastic response and optimal damage repair, the ion fraction in these systems should be in the range of 5 mol% and the chain dynamics should be appropriate to allow for excellent self-healing behavior at moderate healing temperatures.

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Section: Structural Characterizationsupporting

confidence: 88%

Self-healing dynamic bond-based rubbers: understanding the mechanisms in ionomeric elastomer model systems

Hohlbein

Shaaban

Brás

et al. 2015

Phys. Chem. Chem. Phys.

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“…NaEMAA [122] Spheres, 2-15 nm, Spheres, 20-150 nm Compression molding and extrusion. Three regions in a sample, one with no aggregates (however, there was Na present), one with small spherical aggregates, one with large spherical aggregates CsSMAA [123] Spherical vesicular c , 5-20 nm outer diameter, 3 nm thickness walls…”

Section: Compression Moldingmentioning

confidence: 99%

Review and critical analysis of the morphology of random ionomers across many length scales

Grady

2008

Polymer Engineering & Sci

101

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This review presents a description of what is known about ionomer morphology. All papers on ionomer morphology are not included in this review; but all relevant questions about ionomer morphology are posed and answered as completely as possible. The review is critical; that is, reasons are given for morphologies that are deemed to be more or less likely. The review is organized along three length scales: sub-nanometer, nanometer to 10 nm, and greater than 10 nm. Within each length scale, all three phases are considered: crystalline, amorphous, and ionic aggregate. The purity of the three phases, the arrangement of atoms in the three phases, the size and shape of the three phases, and their arrangements in space relative to each other are explored in this review. A model for the shape of aggregates in ionomers that have well-ordered internal environments is presented. This model proposes that aggregates are fundamentally planar, but will ''roll up'' into tubes or other related structures in order to reduce the number of atoms at aggregate edges. This model was developed primarily based on the varied morphologies ionomers have shown in electron micrographs, but is consistent with other indirect measurements of ionomer morphology.

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“…We can suppose, in analogy to the aforementioned ionomer, that in the neutralized copolymers of MANA, associates are small, and in dilute solutions, the ion association is thought to be only 2–3. Unfortunately, these fluorescence measurements, in comparison with the other methods, do not enable us to quantify the dimensions of the associates with, for example, electron microscopy in the solid state 26…”

Section: Resultsmentioning

confidence: 99%

Activity of interferon‐α and isotretinoin in patients with advanced, refractory lymphoid malignancies

Tsimberidou

Giles

Romaguera

et al. 2004

Cancer

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BACKGROUNDInterferon‐α (IFN‐α) and retinoids have shown nonoverlapping toxicity and each has shown antitumor activity in patients with lymphoma. The aim of the current study was to assess the toxicity, safety, and efficacy of IFN‐α combined with isotretinoin in patients with advanced, refractory lymphoid malignancies.METHODSAdults with biopsy‐proven advanced lymphoid malignancy were treated. Patients with compromised bone marrow function (platelet counts as low as 30 × 109/L) were eligible. Treatment was comprised of IFN‐α at a starting daily dose of 3 mega units subcutaneously and isotretinoin orally starting at a dose of 1 mg/kg daily in 2 divided doses.RESULTSForty‐four patients were evaluable. Their median age was 57 years (range, 18–82 years). Eighteen patients had advanced cutaneous T‐cell lymphoma, 6 patients had peripheral T‐cell lymphoma, 14 patients had Hodgkin disease, and 6 patients had a variety of other lymphoid malignancies. Patients with Hodgkin disease had received a median of 6 previous therapies (range, 3–12 therapies) and patients with other lymphoid malignancies had received a median of 4 previous therapies (range, 1–9 therapies). The median duration of treatment was 4 months (range, 0.25–38 months). The overall response rate was 38.6% (complete response in 5 patients [11.3%] and partial response in 12 patients [27.3%]). The median response duration was 3 months (range, 1–95+ months). The most common toxicities were low‐grade fever, flu‐like symptoms, and fatigue (IFN‐α effects); dry mouth and skin and hypertriglyceridemia (cis‐retinoic acid effects); and thrombocytopenia (which generally occurred in patients with low baseline platelet counts).CONCLUSIONSIFN‐α and isotretinoin combination therapy had antitumor activity and was well tolerated in heavily pretreated patients with lymphoid malignancies. Cancer 2004. © 2003 American Cancer Society.

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Vesicular Ionic Aggregates in Poly(styrene-ran-methacrylic acid) Ionomers Neutralized with Cs

Cited by 37 publications

References 12 publications

Self-healing dynamic bond-based rubbers: understanding the mechanisms in ionomeric elastomer model systems

Self-healing dynamic bond-based rubbers: understanding the mechanisms in ionomeric elastomer model systems

Review and critical analysis of the morphology of random ionomers across many length scales

Activity of interferon‐α and isotretinoin in patients with advanced, refractory lymphoid malignancies

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