Carboxylic Rubbers. II. Properties of Cured Stocks

Dolgoplosk, B. A.; Reĭkh, V. N.; Tinyakova, E. I.; Kalaus, A. E.; Koryushenko, Z. A.; Sladkevich, E. G.

doi:10.5254/1.3542391

Cited by 6 publications

(3 citation statements)

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“…However, without covalent crosslinks the ionic rubber network suffers from poor compression set, low elongation at break and reduced tensile strength at higher temperature. Consequently, several authors have proposed that both covalent as well as ionic crosslinks are required to obtain good mechanical properties and ageing stabilities 6, 34, 36, 38–47…”

Section: Resultsmentioning

confidence: 99%

Dual crosslinking of carboxylated nitrile butadiene rubber latex employing the thiol‐ene photoreaction

Lenko

Schlögl

Temel

et al. 2013

J of Applied Polymer Sci

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At present, the most common used crosslinking process for carboxylated nitrile butadiene rubber (XNBR) latex is an accelerated sulfur curing system with zinc oxide. To avoid allergenic reactions related to residual accelerator levels in dipped XNBR latex articles such as medical gloves, a dual curing process has been developed combining thermal and photochemical crosslinking reactions. The two-step procedure involves the formation of covalent and ionic bonds to ensure good mechanical properties of the final products. The photochemical thiol-ene reaction is used to generate covalent crosslinks between the remaining C¼ ¼C double bonds of the butadiene units whereas the carboxylic moieties are conventionally cured with divalent metal oxides (ZnO) under elevated temperature (formation of ionic crosslinks). The photochemical curing step is carried out both in the latex phase using a falling film photoreactor (prevulcanization) as well as in the solid phase by UV irradiation of dried XNBR films (postvulcanization). The mechanical properties and crosslink densities of the cured XNBR films are determined and the influence of selected curing parameters is assessed. The results give evidence that a combined approach of thermal prevulcanization and photochemical postvulcanization makes the production of latex articles (e.g., gloves) with tailored properties and good skin compatibility feasible.

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Section: Resultsmentioning

confidence: 99%

Dual crosslinking of carboxylated nitrile butadiene rubber latex employing the thiol‐ene photoreaction

Lenko

Schlögl

Temel

et al. 2013

J of Applied Polymer Sci

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“…In sulfonated ionomers, it has been repeatedly shown − that Zn produces lower melt viscosities than do other cations, including Na. For carboxylated materials, such comparisons are rarer; early work , on carboxylated rubbers neutralized beyond the stoichiometric point indicates that Zn produces lower viscosities and tensile strengths than most cations, but the excess neutralizing agent may affect such comparisons. One complicating factor is that the activation energies for Na and Zn ionomers differ; however, using the activation energies we have determined, the ratio of Zn to Na viscosities drops only a factor of 2.2 on increasing the temperature from 135 to 200 °C, so the difference in activation energy should not dominate the comparison.…”

Section: Resultsmentioning

confidence: 99%

Low-Shear Melt Rheology of Partially-Neutralized Ethylene−Methacrylic Acid Ionomers

1996

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We examine the melt rheology of a series of ethylene−methacrylic acid (E/MAA) ionomers, all based on the same E/MAA copolymer, with an emphasis on the low-shear-rate Newtonian region. All ionomers show Newtonian behavior at sufficiently low shear rates. The zero-shear viscosity η0 is a strong function of neutralization level and is significantly higher for Zn ionomers than for Na ionomers at the temperatures and neutralization levels examined. The recoverable compliance J e 0 is independent of cation type and neutralization level, indicating that the ionic associations bear no stress during steady flow in the terminal region. Therefore, the individual ionic associations have lifetimes much shorter than the terminal relaxation time of the polymer chain. We probe the effect of unneutralized acid groups on η0 by removing these groups through esterification. Unneutralized acid groups substantially lower the viscosity of Na ionomers but have no discernable effect in Zn ionomers. An “acid-cation exchange” mechanism is proposed to explain these findings.

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“…These results reflect that, for this particular TPV compound, MgO is more effective than ZnO in neutralizing the carboxyl groups present in the rubbery phase. The effects of different oxides and hydroxides of divalent metals in the mechanical properties of a carboxylic styrene butadiene rubber containing 1.5 wt% of carboxylic groups have been studied by Dolgoplosk et al . They found that MgO gives better physical properties than ZnO.…”

Section: Resultsmentioning

confidence: 99%

New ways to improve the damping properties in high‐performance thermoplastic vulcanizates

Burgoa

Hernandez

Vilas

2020

Polymer International

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The incorporation of viscoelastic materials represents an effective strategy to reduce the vibratory level of structural components. Thermoplastic vulcanizates (TPVs) are a special type of viscoelastic material that combines the elastomeric properties of rubbers with the easy processing of thermoplastics. In the present work, we propose innovative ways to improve the damping properties of high-performance TPVs by using rubbers with carboxylic functionalities. For that, TPVs from physical blends of carboxylated hydrogenated acrylonitrile butadiene rubber (XHNBR) and polyamide 6 (PA6) were prepared. The chain dynamics of different mixed crosslink systems containing peroxide, metal oxides and hindered phenolic antioxidants were investigated in order to find the most suitable strategy to design a high-performance TPV system with upgraded damping properties. The results indicate that the damping performance of the TPV system can be tailored by controlling the type and magnitude of the bonding interactions between the mixed crosslink system and the XHNBR rubber phase. Therefore, this study demonstrates the potential of TPV systems containing carboxylic rubbers as high-performance damping materials.

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Carboxylic Rubbers. II. Properties of Cured Stocks

Cited by 6 publications

References 0 publications

Dual crosslinking of carboxylated nitrile butadiene rubber latex employing the thiol‐ene photoreaction

Dual crosslinking of carboxylated nitrile butadiene rubber latex employing the thiol‐ene photoreaction

Low-Shear Melt Rheology of Partially-Neutralized Ethylene−Methacrylic Acid Ionomers

New ways to improve the damping properties in high‐performance thermoplastic vulcanizates

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