Ionomer blends

Our research studies on ionomers and on ionomer blends has received financial support from the U.S. Army Research Office and ACS-PRF, whose assistance is gratefully appreciated. Our appreciation is also expressed to former graduate students, Drs. P. Jar, M. A. Bellinger, and X. Ma, who made significant contributions to some of the research results reported herein. 

Ion nitriding, 16 205 Ionomer blends, 14 476-478 Ionomer food packaging, 13 44 Ionomer peak, 14 464 Ionomer properties, effects of polar plasticizers on, 14 479 Ionomers, 14 460-489... 

Patent Number US 6066393 A1 20000523 POLYOLEFIN/IONOMER BLEND FOR IMPROVED PROPERTIES IN EXTRUDED FOAM PRODUCTS... 

High acid ionomers are neutralized to various extents by several different types of metal cations, such as by manganese, lithium, potassium, calcium and nickel cations. Several types can be blended. It has been found that these by additional cations neutralized high acid ionomer blends produce compositions exhibiting enhanced hardness and resilience due to synergies, which occur during processing (12). 

K. Hausmann, B. Rioux, and J.-M. Francois, Antistatic ionomer blend, US Patent 6630528, assigned to E. I. du Pont de Nemours and Company (Wilmington, DE), October 7,2003. 

Van Zyl AJ and Kerres JA. Development of new ionomer blend membranes, their characterization and their application in the perstractive separation of alkene-alkane mixtures. II. Electrical and facilitated transport properties. J Appl Pol Sci 1999 74 422-427. 

FAIRLEY PRUD HOMME Rheology of Polyethylene—Ionomer Blends 215... 

FAIRLEY PRUD HOMME Uuolagy f Palyetl flem-Ionomer Blends 2 1... 

FAIRLEY PRUD HOMME Rheolofy ofPofyetl /lme—Ionomer Blends... 

Until recently, perfluorinated ionomrs with high equivalent weights were believed to be insoluble. Covitch(50), however, has identified a number of solvents and dissolution procedures for the sulfonyl fluoride precursor and sulfonate and carboxyl ate Nafion ionomers with 1100 to 1200 equivalent weight. This development has great potential for the preparation of sulfonate and carboxyl ate ionomer blends, the... 

Transport properties of ionomer blends, characterized by a given type of spheroids and the aspect ratio, e/a, can now be analyzed by the effective medium theory discussed in the previous section. In this theory, the two phases are assumed randomly mixed and the probability of finding each phase is equal to its volume fraction f.. The effective conductivity, o, of the composite for either Na+ of OH ions is given by (15) ... 

Fig. 7 Current efficiency of carboxylate/sulfonate ionomer blends. Curves are predicted behavior of oriented oblate spheroids whose aspect ratios are 0.01 (top curve), 0.25 (middle curve) and 0.995 (bottom curve), respectively. Reproduced with permission from Ref. 15, Fig. 2. Copyright 1983, American Chemical Society.

In summary, I have discussed a semi-phenomenological elastic theory for ion clustering in ionomers. The theory is consistent with observed trends in perfluorinated ionomers. I have also demonstrated the percolatlve nature of ion transport in these ionomers and computed quantitatively their tensile modulus. Finally, I have discussed the Influence of morphology on ion selectivity in perfluorinated ionomer blends. In particular, I have pointed out that an universally preferred morphology beneficial to all blends does not exist the ideal morphology must be individually determined based on component properties. Most of the theories and conclusions here are very general and applicable to other composite polymer systems. 

Many ionomers are used in polymer blends as a compatibilizer, because the ionomers have at least two different properties, that is, hydrophobic host-polymer matrix and hydrophilic ionic groups and/or aggregates. In addition, the solution properties of mixtures including the ionomers have also been investigated to clarify the details of characteristics not only in blending but also in micellar structures. For example, Bosse and Eisenberg recently reported on the kinetics of coil overlap in ionomer blends in DMSO by means of H NMR.47,48... 

Favis [1994] and Willis andFavis [1988] prepared compatibilized PA blends with PP and carboxylic acid-functionalized EMAA ionomer. Blends containing 90-10 parts PA-6, 0-30 parts EMAA ionomer, and 10-90 parts PP were combined in an internal mixer at 250°C and characterized by torque rheometry and SEM. Dispersed phase particle size vs. interfacial modifier concentration was determined. Emulsification curves were constructed. Effects of mixing protocol on blend properties were studied. Blends were also prepared containing HOPE in place of PP. 

Commercial ionomers are ethylene-methacrylic acid copolymers and terpolymers in which the carboxylic acid moiety is partially neutralized with sodium or zinc, to promote interchain ionic bonding. Ionomers exhibit excellent low temperature toughness, chemical resistance and adhesion. However they lack in stiffness and heat resistance. Hence ionomer blends with polyolefins such as polyethylene have been developed which, upon reinforcing with suitable fillers, seem to give a unique combination of high strength, excellent low temperature toughness, and moderate stiff-... 

Figure 15.6. Morphology of typical Polyamide/impact modifier blends — TEM., Phosphotungstic acid stain, top — PA-6/ethylene copolymer/ionomer blend (21,000X) bottom — PA-6/maleated EPR (3 1) blend (30,000X).

The apparatus is described and details given of its use with PETP homopolymer, PS/poly(vinyl methyl ether) miscible blend and styrene-styrenesulphonic acid copolymer/ethyl acrylate-4-vinylpyridine copolymer ionomer blend with ionic interactions. Orientation and relaxation curves were obtained for all three samples. It is concluded that the technique is very efficient for obtaining curves with high precision. For these three systems, the relaxation rate increases with temperature. 

For PETP, a reorientation as a function of time was observed. This phenomenon is dependent on temperature and draw ratio, and is probably due to the crystallisation of the sample. For the PS/poly(vinyl methyl ether) blend, the addition of poly(vinyl methyl ether) to the blend increased the orientation of the PS chains during the stretching. Forthe ionomer blends, the orientation of both types of chain was higher when the ionic content increased. 4 refs. 

Formion lonomer compounds PO/ionomer blends A. Schulman, Inc. 

One promising approach to producing a true molecular composite is to make rod and coil components thermodynamically miscible by introducing attractive interactions, such as hydrogen bonds (16-18), between them. This method has proven useful for enhancing miscibility in flexible-flexible blends. Even more useful (stronger) interactions may be ionic interactions, such as ion-ion and ion-dipole interactions various studies on ionomer blends have demonstrated that ionic interactions can enhance the miscibility of otherwise immiscible polymer pairs (79). Polymers studied include polystyrene, poly(ethyl acrylate), poly(ethyleneimine), nylon, and poly (ethylene oxide) (20-22). 

Low barrier HDPE/EVA HDPE/HDPE/EVA HDPE/HDPE/EVA-ionomer blend... 

Since it is not possible to describe all the ionomer families in this article, we will just name a few more extensively studied ionomers here pol5nirethane ionomers (152—155), polypentenamers (156,157), ionenes (158—160), polysiloxane dizwitterionomers (161,162), ethyl (or butyl) acrylate zwitterionomers (163,164), ethyl acrylate ionomers (165—167), methyl methacrylate ionomers (168—171), and liquid crystalline ionomers (172—179). An area which has been a subject of considerable investigation bnt not discussed here is ionomer blends. Some reviews summarize this subject, and thus interested readers are referred to those review articles (180-183). It should also be mentioned that even though the solution properties of ionomers are of great importance, the discussion on the topic is omitted readers who are interested in the topic can look up other review articles (184 -187). 

Eisenbach C D, Hofmann J and MacKnight W J (1994) Dynamic-mechanical and spectroscopic study of ionomer blends based on carboxylated or sulfonated flexible polystyrene and rigid poly(di-acetylenes) with functional side groups. Macromolecules 27 3162-3165. 

Kerres J, Ullrich A, Haring T (2004) Engineering ionomer blends and engineering ionomer blend membranes. European Patent 1,076,676 US Patent 6,723,757... 

Kerres J, Zhang W, Haring T (2004) Covalently cross-linked ionomer (blend) membranes for fuel cells. J New Mater Electrochem Syst 7 299-309... 

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