X-ray absorption spectroscopy studies of zinc-neutralized ethylene-methacrylic acid ionomers

Grady, Brian P.; Floyd, J; Genetti, W. B.; Vanhoorne, Pierre; Register, Richard A.

doi:10.1016/s0032-3861(98)00239-0

Cited by 35 publications

(61 citation statements)

References 16 publications

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“…A clear qualitative difference was found, with zinc it was concluded (and later confirmed via XAS [70]) that the free acid groups did not interact with the aggregates, while the free acid groups did interact with the sodium ionic aggregates. In other words, the polymer, at least that part of the polymer that contained free acid groups, must be involved with the ionic aggregates in sodium-neutralized EMAA.…”

Section: Ionomer Synthesismentioning

confidence: 86%

“…In sulfonated polystyrene neutralized with zinc [72,73], nickel [74] and cadmium [75], zinc-neutralized EMAA and ethylene-acrylic acid (EAA), [70] carboxyterminated polybutadiene neutralized with zinc, [76] titanium [77] or iron, [77] the environment around the cation was very ordered. Note that all of these cations can form coordination bonds.…”

Section: Ionomer Synthesismentioning

confidence: 99%

“…Examples of analogous small molecule compounds include monoclinic anhydrous zinc acetate for zinc neutralized EMAA and EAA, [70] cadmium methane sulfonate dihydrate, and cadmium acetate dehydrate for cadmium-neutralized SPS and EMAA, respectively [75]. Figure 4A schematically represents the structure inside an aggregate of the zinc-neutralized EMAA or EAA ionomer.…”

Section: Ionomer Synthesismentioning

confidence: 99%

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

Grady

2008

Polymer Engineering & Sci

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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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Section: Ionomer Synthesismentioning

confidence: 86%

Section: Ionomer Synthesismentioning

confidence: 99%

Section: Ionomer Synthesismentioning

confidence: 99%

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

Grady

2008

Polymer Engineering & Sci

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101

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“…Ionomer retains pseudcross-linked structure mediated by ionic aggregates. Due to the existence of ionic aggregates, stiffness and impact resilience of EMAA ionomer are higher than those of EMAA [1][2][3][4][5][6][7][8] .…”

Section: Introductionmentioning

confidence: 96%

Strong Attractive Interaction between Ethylene Ionomer and Carboxyl Groups of Styrene-Co-Methacrylic Acid

Takaki

Koda

Haba

et al. 2017

J. Soc. Rheol., Jpn

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Effects of styrene-co-methacrylic acid (StMAA) on melt viscosity and morphology for ethylene ionomer were studied. In this study, we used poly-(ethylene-co-methacrylic acid) of neutralization degree 54 % with sodium ions (EMAA54Na). Dynamic viscoelasticity of EMAA-54Na/polystyrene(PS) or EMAA-54Na/StMAA blends was evaluated. EMAA54Na/StMAA blends differed from EMAA-54Na/PS blends in rheological property. Zero shear viscosity η 0 of EMAA54Na/StMAA was higher than expected viscosity with increasing contents of StMAA. Furthermore, fall down of the damping function obtained from stress relaxation measurement of EMAA-54Na/StMAA was weaker than that of EMAA54Na. These results indicated strong interaction between EMAA ionomer and carboxyl groups of StMAA. Results of morphological observation and Fourier transform infrared spectroscopy also indicated that the strong interaction is attractive.

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“…4,5 These ionomers contain typically 15 mol % or less MAA which are partially neutralized with metal cations, [6][7][8][9] such as Zn 2+ and Na + . It is believed that aggregation of ionic pairs, such as -O --Na + , plays a crucial role in determining the unique properties of Surlyn.…”

Section: Introductionmentioning

confidence: 99%

NMR Study of Structure and Dynamics of Ionic Multiplets in Ethylene−Methacrylic Acid Ionomers

Jia

Kleinhammes

2005

Macromolecules

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Structural and dynamical properties of ionic multiplets in poly(ethylene-co-methacrylic acid) ionomer neutralized with Na ions were studied by 23 Na nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC). It was found that the low-temperature peak in DSC spectra is affected by relaxation, compression, and hydration and is related to structure in proximity to ionic multiplets, instead of multiplets themselves. The distance between Na ions in ionic multiplet was determined on the basis of a second moment measurement, suggesting that multiplets are composed of close-packed Na + -O -ionic pairs. Motional narrowing of 23 Na NMR line width and transverse relaxation measurement indicate that the time scale of motion of Na or its surrounding is on the order of a few hundred microseconds near room temperature. IntroductionIonomers derived from neutralization of ethylene/ methacrylic acid (E/MAA) copolymer, known as Surlyn, possess unique mechanical, rheological, and thermal properties 1-3 as well as the intriguing property of selfhealing. 4,5 These ionomers contain typically 15 mol % or less MAA which are partially neutralized with metal cations, 6-9 such as Zn 2+ and Na + . It is believed that aggregation of ionic pairs, such as -O --Na + , plays a crucial role in determining the unique properties of Surlyn. 1-3 Many tools have been used in studying the microstructure of Surlyn, including small-angle X-ray scattering (SAXS), 10-13 differential scanning calorimetry (DSC), [1][2][3]8,12,13 infrared spectroscopy (IR), 12 and nuclear magnetic resonance (NMR). 1,8 Scattering studies such as SAXS indicate that ionic pairs attract each other forming aggregates, called multiplets. 15 It is generally accepted that there are three regions in Surlyn: polyethylene crystalline lamellae, amorphous matrix, and multiplets of ionic pairs. The formation of ionic multiplets is believed to have a profound influence on the mechanical, thermal, and other physical and chemical properties. Previous DSC studies showed that two endothermic peaks are present upon heating of structurally relaxed (aged) Surlyn. The higher temperature peak, around 90°C, is attributed to the melting of polyethylene crystalline lamellae. 2,8,12,16 The identity of the low-temperature peak around 50°C remains unclear. This peak is absent in samples immediately after cooling from the melt and recovers after a certain period of structural relaxation at room temperature. 2,8,12,16 It was found that this low-temperature peak is also affected by hydration 14 and stretching. 13 One of the proposed explanations is the order-disorder transition of the ionic multiplet. 2,16 Others suggest that this peak is associated with the melting of imperfect crystallites of short segment polyethylene or changes occurring in the region surrounding the ionic multiplet rather than the ionic multiplet itself. 13 NMR is a sensitive probe of local structures and dynamics. 23 Na NMR provides a natural probe of the structure and dynamics of ionic

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X-ray absorption spectroscopy studies of zinc-neutralized ethylene-methacrylic acid ionomers

Cited by 35 publications

References 16 publications

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

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

Strong Attractive Interaction between Ethylene Ionomer and Carboxyl Groups of Styrene-Co-Methacrylic Acid

NMR Study of Structure and Dynamics of Ionic Multiplets in Ethylene−Methacrylic Acid Ionomers

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