On the mechanism of ozone degradation of SBR

Delman, A. D.; Simms, B. B.; Ruff, Alexander

doi:10.1002/pol.1960.1204514611

Cited by 9 publications

(5 citation statements)

References 32 publications

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“…Therefore, several research groups have studied thermal and oxidative degradation processes of simple, single rubber polymers. Delman et al studied the degradation of SBR in the presence of ozone and oxygen. The ozonization was performed at room temperature, employing toluene solutions of SBR.…”

Section: Introductionmentioning

confidence: 99%

Depolymerization of Styrene−Butadiene Copolymer in Near-Critical and Supercritical Water

Park

Hool

Curtis

et al. 2001

Ind. Eng. Chem. Res.

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Many conventional solvents do not sufficiently dissolve cross-linked polymers such as styrenebutadiene rubber (SBR) to allow efficient depolymerization. Supercritical and near-critical water provides an alternative benign solvent for this application. Supercritical water oxidation and thermal degradation under supercritical water conditions provide a means to break down rubbery materials into organic compounds that can then be recovered as a chemical feedstock. In this study, depolymerization reactions of styrene-butadiene copolymer are examined in a semicontinuous reactor. A statistical experimental analysis technique was used to investigate the effect of various operating conditions: temperature (300-450 °C), pressure (135 and 170 bar), and the presence of hydrogen peroxide as an oxidant (0-5 wt %). The experimental results demonstrate the ability of supercritical and near-critical water to break down the SBR into a range of lower molecular weight organic compounds for potential recovery. Analysis of variance (ANOVA) shows that the temperature and oxidant concentration are significant at the 1% level for destruction efficiency. Benzene, toluene, ethylbenzene, styrene, phenol, acetophenone, benzaldehyde, and benzoic acid are identified as liquid products using gas chromatography in both batch and semicontinuous reactors. The gas products were comprised of carbon monoxide, carbon dioxide, and water as determined by Fourier transform infrared spectroscopy. The destruction efficiency and a semiquantitative analysis of the liquid products show that both pyrolysis and oxidation products are observed, and low molecular weight oxidation products are observed to be primary.

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Section: Introductionmentioning

confidence: 99%

Depolymerization of Styrene−Butadiene Copolymer in Near-Critical and Supercritical Water

Park

Hool

Curtis

et al. 2001

Ind. Eng. Chem. Res.

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“…Ozone has a forceful reaction activity compared with oxygen even at room temperature, resulting in more intensive degradation of polymers, even if the concentration of ozone is very smaller than that of oxygen in air atmosphere. Criegee 16 proposed that ozone induces the autocatalytic degradation of randomly polymerized SBR, and evidences have been presented by several investigators to show that ozone attacks olefinic compounds through the double bond, 3,35 exemplifying the ozonization reaction mechanism shown in Fig. 15.…”

Section: Changes In Morphology and Chemical Properties During The Ozo...mentioning

confidence: 99%

“…This presumption is based on the similarity of the p electron cloud and the conjugated double bonds, in other words, the similar electron-withdrawing groups. It should be pointed that O 3 is composed of a O 2 molecule and a coordinated O atom, and a rapid ozone reaction will be completed after a electrophilic rearrangement between O 3 and a delocalized p-bond, 16 which is different from the radical adsorption between an R radical and the delocalized p-bond of fGO. 15 To test and verify this presumption, a comparative experiment has been designed and followed.…”

Section: Changes In Morphology and Chemical Properties During The Ozo...mentioning

confidence: 99%

“…15 Ozonization severely influences the degradation and lifetime of alkene elastomers, and ozone is increasing in the atmosphere recently because of the increase in UV irradiation and nitrogen oxide atmospheric pollutants. 16 Accordingly, sufficient attention should be paid to ozone aging also as few literature reports investigate the effect of ozone on the stabilization of polymer composites.…”

Section: Introductionmentioning

confidence: 99%

“…Fig 16. Relationship between carbonyl index and ozonization time for the pristine and the n-fGO nanocomposites.…”

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confidence: 99%

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Thermal oxidative and ozone oxidative stabilization effect of hybridized functional graphene oxide in a silica-filled solution styrene butadiene elastomer

Zhao

Huang

et al. 2016

Phys. Chem. Chem. Phys.

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Hybridization of modified functional graphene oxide (fGO) in silica-filled solution styrene butadiene rubber (SSBR) endows preferable tensile and dynamic properties before and after thermal oxidative aging, and similar mechanical hysteresis performance compared with the composites without fGO. The preventing mechanism of fGO is attributed to its intrinsic peroxy radical scavenging and gas barrier abilities, which significantly reduces the peroxy radical concentration and oxygen permeability of nanocomposites and then prolongs oxidative induction time (OIT), characterized by differential scanning calorimetry (DSC). The ozone resisting effect of different loadings of fGO on nanocomposites have also been investigated by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) after ozonization under 50 ppm ozone concentration. As a result, incorporation of fGO apparently suppresses both the formation of oxygenic groups of the olefinic elastomer and crack morphology extension upon ozonization. We propose that fGO protects the SSBR elastomer from ozone attack through the conjugated delocalized π-bonds of the fGO instead of the C[double bond, length as m-dash]C bonds of the elastomer matrix being attacked, and the compared experiments, characterized by X-ray photoelectron spectroscopy (XPS), confirm that this presumption is perhaps reasonable. Moreover, more than 3 phr incorporation of fGO in nanocomposites deteriorates the chemical and mechanical properties of the elastomer during the thermal oxidation and ozonization because of the cleavage influence of oxygenic groups on peroxy radicals.

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Fractionation of Polymers

Barrales‐Rienda

Bello

et al. 1999

The Wiley Database of Polymer Properties

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On the mechanism of ozone degradation of SBR

Cited by 9 publications

References 32 publications

Depolymerization of Styrene−Butadiene Copolymer in Near-Critical and Supercritical Water

Depolymerization of Styrene−Butadiene Copolymer in Near-Critical and Supercritical Water

Thermal oxidative and ozone oxidative stabilization effect of hybridized functional graphene oxide in a silica-filled solution styrene butadiene elastomer

Fractionation of Polymers

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