Ethylene-methacrylic Acid Research Articles

Infrared Spectral Change in a Zinc Salt of an Ethylene-Methacrylic Acid Ionomer on Water Absorption

Local structural change in the ion aggregate in a zinc salt of poly(ethylene-co-methacrylic acid) ionomer on water absorption-desorption process was investigated with use of infrared spectral change in the carboxylate antisymmetric stretch region. Three bands were found at 1539, 1560, and 1625 cm−1 in dried state. They collapsed into a singlet at 1587 cm−1 on swelling. The spectral change occurred reversibly with respect to the water content at a constant temperature. Analyzing the ratio of the relative integrated intensities of the dry state to the wet one, we evaluated the hydration number to a Zn2+ ion in the wet state. The difference in molar absorption coefficients of the bands between the dry and wet states can be explained by the vibrational coupling between the va (COO−) and carboxylate rocking P (COO−) modes.

Coionomeric mixtures of polyhydroxyethers and ethylene methacrylic acid copolymers. I. Effects of cation concentration and ABA oligomeric miscibilisers on morphology and properties

AbstractMixtures of a phenoxy polymer (polyhydroxyether of bis‐phenol A) and a polyolefin ionomer (sodium ionomer of ethylene methacrylic acid copolymer) were compatibilized by the addition of small amounts of sodium ethoxide and/or by the incorporation of varying amounts of A‐B‐A block oligomers. The latter were produced by reacting several bis‐phenol A epoxy resins, varying in molecular weight, with montanic acid in order to provide segments soluble in each of the two polymer components of the blend. Chemical miscibilization by the addition of sodium ethoxide changed the morphology into one containing larger amounts of cocontinuous phases, while the incorporation of substantial amounts of A‐B‐A oligomer brought about primarily the formation of irregular and highly elongated particles. The mixtures were found to exhibit the typical properties of ionomers which were enhanced by the addition of sodium ethoxide. Furthermore sufficient evidence was gathered to establish that the ionomeric aggregates are shared by both polymer components of the blend, from which the term coionomeric mixture is derived. © 1993 John Wiley & Sons, Inc.

Coionomeric mixtures of polyhydroxyethers and ethylene methacrylic acid copolymers. II. Compatibilizers for blends of polybutylene terephthalate and ethylene butyl acrylate copolymers

AbstractBlends of polybutylene terephthalate and ethylene butyl acrylate copolymers were studied at two extreme concentration levels so that each polymer would form, in turn, a particulate dispersed phase. The blends contained 5% by weight of a coionomeric compatibilizer, which was produced from 1 : 1 mixtures of a polyhydroxy ether of bisphenol A and the sodium ionomer of an ethylene methacrylic acid copolymer, using sodium ethoxide to enhance the formation of ionomeric clusters together with an A‐B‐A block oligomer to assist the solubilization of the two ionomeric polymers. In all cases the addition of the coionomeric compatibilizer mixture to the blend was found to decrease the size of the dispersed particles with a concomitant reduction in the interphase gap. It was also observed that the dispersed polymer exhibited a lower level of crystallinity and a slightly lower melting point than when it was present as a matrix, particularly for the case of the ethylene butylacrylate copolymer. The inability of the compatibilizer to completely prevent the formation of an interfacial gap which did not allow the blends to achieve more substantial improvements in mechanical properties, was attributed to the vast difference in crystallization temperature between the two polymers. © 1993 John Wiley & Sons, Inc.

Dielectric relaxation studies on water absorption of ethylene ionomers

Sodium and zinc salts of ethylene-methacrylic acid (5.4 mol %) copolymer (EMAA-xNa(or Zn)-yH 2 O, where x and y are degree of neutralization and molar ratio of H 2 O to COONa, respectively) were studied. The dielectric relaxations of EMAA and EMAA-0.6Zn, whose water absorption is usually small, were scarcely affected by water uptake. On the other hand, the dielectric relaxations of EMAA-xNa, particularly highly neutralized sodium salts, sensitively responded to water uptake. The results indicated that three water molecules per sodium cation form a primary hydration shell and that the excess waqter molecules are absorbed around that shell. It is concLuded that the ionic clusters are probably transformed into a structure reminiscent of an inverse micelle upon water absorption

Ethylene–methacrylic acid copolymers as stress whitening suppressants in polypropylenes

AbstractImpact‐modified polypropylenes were prepared by incorporating copolymers of ethylenemethacrylic acid (E‐MAA) with different cations (zinc or sodium) and varying degrees of neutralization. These blends gave low stress whitening on impact. This phenomenon was due to the unique morphology of the blend. It was found that unneutralized acid copolymer and the zinc ionomer formed chainlike structures in the polypropylene matrix. These uniform chains crisscrossed the polypropylene matrix providing impact strength to the matrix. The matrix deformed on impact by the shear yielding mechanism, thus suppressing stress whitening. The impact modifier in the matrix did not form micro crazes in the matrix but formed several layers of crisscrossing chains. On the other hand, the sodium ionomer did not form chainlike structures. The impact modifier was dispersed evenly in the matrix. This type of morphology resulted in a higher degree of stress whitening. The failure on impact was due to crazing and not by shear yielding. This size of the impact modifier in the polypropylene matrix varied significantly depending on the melt processing equipment used. The dependence of polymer alloy mechanical properties on the composition has been studied to help in ionomer comparison.

EXAFS studies on Zn(II) complexes with 1,3-bis(aminomethyl)cyclohexane of ethylene-methacrylic acid copolymer

Extended X-ray absorption fine structure (EXAFS) experiments were performed at 25 and 105°C for Zn(II) salts of ethylene-methacrylic acid (5.4 mol%) copolymer and their complexes with 1,3-bis(amino-methyl)cyclohexane (BAC) (EMAA-Zn-BAC). The zinc carboxylate in EMAA-Zn-BAC systems was in a four-fold coordination at room temperature. The ZnO distance increased with increasing BAC content, and became smaller at 105°C than at room temperature for EMAA-0.60Zn and EMAA-0.60Zn-0.40BAC but scarcely changed with temperature for EMAA-0.60Zn-0.97BAC. The fluctuation factor (σ) was larger at 105°C than at room temperature for all the samples, due to thermal vibration. In this paper, it is pointed out that these EXAFS results support the presence of an order-disorder transition in ionic clusters.

Far-infrared study on the zinc(II) complex salts of ethylene-methacrylic acid copolymer with 1,3-bis(aminomethyl)cyclohexane

Far-infrared study on the zinc(II) complex salts of ethylene-methacrylic acid copolymer with 1,3-bis(aminomethyl)cyclohexane

Ionomers: Two formation mechanisms and models

AbstractThe FT IR spectra for different degrees of neutralization of ionomers based on poly(ethylene–methacrylic acid) copolymer were obtained. They involve the alkali metal ions (such as lithium, sodium, potassium, rubidium, and cesium), the alkaline earth metal ions (such as magnesium, calcium, strontium, and barium), and the transition metal ions (zinc and copper). Through the analysis of these spectra it can be deduced that there are two formation mechanisms and corresponding models for the ionomers: a cluster–multiplet model and a coordinated complex model. Also, it can be seen that the metal cations play an important role in the structure of an ionomer. By comparing the spectra of the metal ionomers at different temperatures as well as the spectra of the metal ionomers before and after water immersion, the existence of the two formation mechanisms and models can be inferred further.

Conductivity anomaly in the zinc(II) complex salts of ethylene-methacrylic acid copolymer with 1,3-bis(aminomethyl)cyclohexane

La conductivite electrique du complexe poly(ethylene-co-acide methacrylique) neutralise a 60% par les ions Zn 2+ /1,3-bis(aminomethyl) cyclohexane (40% relativement a l'acide carboxylique) presente un maximum lors d'un premier chauffage vers 325K, maximum qui n'apparait plus lors du refroidissement et lors du 2eme chauffage a 325 o K mais reapparait apres stockage. Cette anomalie est attribuee a une transition ordre-desordre affectant les agregats ioniques

Complete esterification of ethylene–methacrylic acid and ethylene–acrylic acid copolymers by reaction of their salts with ethyl iodide

Complete esterification of ethylene–methacrylic acid and ethylene–acrylic acid copolymers by reaction of their salts with ethyl iodide

Effect of organic amine type on the structure and properties of the complex Zn(II) salts of ethylene–methacrylic acid copolymer with organic amines

AbstractThe complex Zn(II) salts of ethylene–methacrylic acid copolymer (EMAA) were synthesized by using various organic amines from monoamines to polyamines, from primary amines to tertiary amines, and from molecular amines to polymer amines. Thermal analyses by differential scanning calorimetry (DSC), and the measurement of stiffness, melt flow rate (MFR), and dielectric properties were employed for the complex salts. It was found that the valence, strength of base, rigidity and flexibility, and bulkiness of the organic amines affect the degree of crystalline order of the ionic crystallites, which governs the stiffness of the complex ion ionomers. The stiffness is higher for the complex salts which form the higher orderliness in the ionic aggregates. The organic amines with two or more primary aliphatic amino groups and higher boiling temperatures from more rigid ionic crystallites in the complex ion ionomers leading to the enhanced modulus. Monoamines or polyamines with amino groups attached to flexible chains such as polyether and polysiloxane scarcely develop ionic crystallites and preferentially solvate the amorphous region including ionic groups leading to the decreased modulus. These results provide us with the fundamental information to control the modulus of ionomers.

Oxygen molecule adsorption in cobalt(II) salts of ethylene-methacrylic acid copolymer

L'etude par spectrometrie UV-visible et RPE en fonction du temps et de la temperature suggere que l'adsorption d'O 2 entraine la formation d'un complexe de structure Co(III)-O 2 .− , avec une deformation de l'environnement octaedrique de Co(II)

Small-angle x-ray scattering study for structural changes of the ion cluster in a zinc salt of an ethylene-methacrylic acid ionomer on water absorption

Small-angle x-ray scattering study for structural changes of the ion cluster in a zinc salt of an ethylene-methacrylic acid ionomer on water absorption

EXAFS Analysis of Size-Constrained Semiconducting Materials

Semiconducting materials such as CdSe, CdS, PbS and GaP are included in crystalline zeolite Y and mordenite and structurally flexible ethylene-methacrylic acid copolymer solid matrices. EXAFS analysis reveals formation of species with dimensions of molecular size up to ca. 13 A in the crystalline hosts, while the polymer matrices allow agglomeration of larger semiconducting particles. Zeolite anchored structures are distinctively different to small particles with bulk crystal structure as usually found in colloidal systems.

Selective oxygen gas sorption of complex manganese(II) salts of ethylene-methacrylic acid copolymer with 1,3-bis(aminomethyl)cyclohexane

Adsorption selective de l'oxygene gazeux sur les agregats ioniques formes par les complexes Mn(II)/bis-aminomethyl cyclohexane

Small Angle X-Ray Scattering on Poly(Ethylene-Methacrylic Acid) Lead and Lead Sulfide Ionomers

ABSTRACTThe morphology of ionomers, e.g., poly(ethylene-methacrylic acid) (EMA) lead salts (EMA/Pb) and lead sulfide compounds (EMA/PbS), has been studied by using the techniques of small angle x-ray scattering (SAXS), anomalous SAXS (ASAXS), wide angle x-ray scattering (WAXS), and differential scanning calorimetry (DSC). EMA/Pb containing less than 5 wt% of lead exhibited two characteristic SAXS peaks which corresponded to the lamellar structure of the partially crystalline polymer matrix and the ionic structure of the lead aggregates that were present in the amorphous regions. The lead aggregates were not distributed uniformly and increased in packing density with increasing lead content. Both DSC and WAXS showed that the crystalline phase was present for all EMA/Pb samples and that the crystallinity decreased slightly with increasing lead content. ASAXS near the L3 absorption edge of lead permitted the extraction of the scattered intensity of lead ions from the SAXS patterns of the superimposed crystalline and ionic structures. Correlation function analysis revealed that the ionic aggregates of the EMA/Pb containing 5 wt% of lead could be described by a liquid-like model with a short range order of 2-4 nm. EMA/PbS samples were made by a reaction of EMA/Pb ionomers with hydrogen sulfide. Instead of an ionic peak as shown by EMA/Pb samples, the SAXS patterns of EMA/PbS showed a broad diffraction peak located at the same q value as the lamellar peak of the EMA in acid form. The (lamellar) peak could be attributed to the interference between the PbS crystallites in the neighboring lamellae.

Review and Critical Analyses of Theories of Aggregation in Ionomers

Abstract In general, ionomers are ion-containing polymers [1] which, in contrast to the traditional ion-exchange resins [2], are usually rendered insoluble through the presence of crystalline do-mains. This review will be confined to a discussion of linear organic polymers having fixed ionic sidechains of exclusively either positive or negative charges, examples of which would include the ethylene-methacrylic acid copolymer salts, sulfonated polystyrene, and Nanon perfluorosulfonate salts. More complicated systems, such as those containing zwitterion moieties, polysalts, halato-telechelics, or polyether-salt complexes, will not be of interest herein.

Poly(ethylene terephthalate) blends for permeability barrier applications

AbstractPoly(ethylene terephthalate) (PET) offers good properties as a material of choice for various packaging, electronic, and other applications. In these applications in general, the PET articles achieve improved toughness and other physical properties through molecular orientation resulting from stretching at temperatures slightly above its Tg. Without such orientation, these articles suffer from poor impact toughness. We have been investigating modifications of PET for improving toughness and retaining the permeability properties. PET having intrinsic viscosities of 0.5 to 0.7 have been modified with low modulus polymers, particularly ethylene copolymers such as ethylene‐methacrylic acid (EMAA) copolymers. The effect of crystallinity on toughness was determined. The crystallinity was established by Differential Scanning Calorimetry (DSC) techniques. Many of these modified PET compositions have good toughness and permeability barrier properties for various packaging and other controlled permeability applications such as containers and films.

Dielectric properties of complex salts of Zn( ii) salts of ethylene-methacrylic acid copolymer with 1,3-bisamino-methylcyclohexane

Dielectric relaxations in complex salts of Zn(II) salts of ethylene-methacrylic acid copolymer (E-MAA), MAA content 5.4 mol%, with 1,3-bisaminomethylcyclohexane (BAC) were studied in detail. In E-MAA and the Zn(II) salts, β′ and γ relaxations were observed around 320 and 190 K at 1 kHz, which are attributed to micro-Brownian molecular motion of long segments and local molecular motion of short segments. When BAC is added to the two polymers, the β′ relaxation was replaced by α and β relaxations. The α and β relaxations were related to a glass-rubber transition of ionic clusters and to molecular motion of isolated salts and carboxylic acid not incorporated into the ionic clusters, respectively. From the above results, it was concluded that BAC strongly promotes the formation of ionic clusters.

Degradation of synthetic polymers: Application of some pyrolysis methods in an investigation of the degradation behaviour of ionomers containing methacrylate salt units

Three commercial ionomers, comprising a zinc ion and two sodium ion derivatives of ethylene-methacrylic acid copolymer have been studied; the corresponding homopolymers, polyethylene, sodium polymethacrylate and zinc polymethacrylate have also been examined under the same experimental conditions as a basis for comparison. Infrared spectra of the ionomers indicate the presence in the chains of COOH groups as well as the carboxylate salt structure. Thermogravimetry, differential scanning calorimetry and thermal volatilisation analysis (TVA) are the pyrolysis methods which have been used. The last of these techniques gives the greatest amount of information, since it provides acces to each of the various product fractions (non-condensable gases, condensable gases and volatile liquids, tar/wax fraction and involatile residue) for further investigation. The condensable volatile products have been separated by subambient TVA prior to identification. The ionomers have been found to differ only slightly in stability from polyethylene. From the evidence obtained, it is concluded that degradation occurs first at the salt units in the predominantly polyethylene backbone. The mechanism is discussed.