• Elastomers and Composites
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• v.53 no.3
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• pp.168-174
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• 2018

Natural rubber (NR) and bromo-isobutylene-isoprene rubber (BIIR) were compounded with other formulation chemicals through polymer blending via a mechanical mixing method. After rubber vulcanization by hot-press compression molding, the cure characteristics, mechanical properties, and ozone resistance of the NR/BIIR blends were measured. As the BIIR content increased, the maximum torque of the blends decreased, while the optimum cure time and scorch time tended to increase. Furthermore, the hardness of the blends increased with increasing BIIR content, reaching the maximum value at 75 wt% BIIR, and decreased with a further increase in the BIIR loading. The tensile strength and elongation at break decreased with an increase in the BIIR content, reaching the minimum value at 75 wt% BIIR, and increased with a further increase in the BIIR content. In the ozone resistance test, cracks were not generated when the BIIR content was more than 75 wt%.

• Elastomers and Composites
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• v.47 no.2
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• pp.148-155
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• 2012

EPDM, IIR, and BIIR composites were thermally aged and the crosslink density changes were investigated. Crosslink densities of the EPDM composite increased with increasing the aging time and temperature, whereas those of IIR and BIIR composites for long-term aging at high temperatures tended to decrease. Activation energies for the crosslink density changes of the EPDM composite were higher than those of the BIIR one. The experimental results were explained with the number of allylic hydrogens, activation of the zinc complex, the steric hindrance effect, and oxidation of rubber chain.

• Elastomers and Composites
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• v.27 no.1
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• pp.20-26
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• 1992

Reactions between chlorinated or brominated poly(isobutylene-isoprene) (CIIR and BIIR, respectively) and 3-mercaptopropyltrimethoxysilane(MPS) were kinetically studied by gas chromatography in solution state. CIIR and BIIR were mixed with MPS and dibutyltin dilaurate as catalyst on roll mill and then the compounds were cured in hot water or atmosphere. From the gas chromatography, reaction order, activation energy, and frequency factor were determined. Crosslinking density and physical properties of moisture-cured CIIR and BIIR were measured. CIIR and BIIR were effectively moisture-cured and physical properties of these rubbers were comparatively good.

• Elastomers and Composites
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• v.46 no.2
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• pp.102-111
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• 2011

The innerliner for a tire has excellent impermeability, air retention and good flex properties. The innerliner offers a role to improve performance parameter, such as air retention and tire durability that is of praricular importance for commercial tires. In order to improve the gas barrier properties of a innerliner, most of the innerliner rubbers, such as a halogenated butyl rubber(HIIR), brominated poly(isobutylene-co-isoprene)(BIIR), brominated polyisobutylene-co-paramethylstyrene(BIMS) are used as nanocomposites with nano fillers such as silicates, graphite etc. Innerliners based on nanocomposites may allow gauge adjustments and permeability reductions with potential improvement in tire durability. This article discusses potential innerliner permeablity reduction and compounding parameters on the properties of nanocomposite based innerliners.

• Elastomers and Composites
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• v.49 no.1
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• pp.43-52
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• 2014

The effect of nanoclay (Cloisite 20A) on the self-adhesion behavior of uncured brominated-isobutylene-isoprene rubber (BIIR) has been studied. The dispersion state of nanoclay into the rubber matrix was examined by SEM, TEM and XRD analysis. The thermal degradation behavior of the filled and unfilled samples was examined by TGA and improvement in the thermal stability of the nanocomposites occurred based on the weight loss (%) measurements. Also, addition of nanoclay enhanced the cohesive strength of the material by reinforcement action thereby reducing the degree of molecular diffusion across the interface of butyl rubber. However, the average depth of penetration of the inter-diffused chains was still adequate to form entanglement on either side of the interface, and thus offered greater resistance to peeling, resulting in high tack strength measurements. The improvement in tack strength was only achieved at critical nanoclay loading above 8 phr. Contact angle measurement was also made to examine the surface characteristics. There was no significant interfacial property change by employing the nanoclay.