About the activation energies of the main and secondary relaxations in cured styrene butadiene rubber
This article studies the influence of the network structure on the activation energies of the a and b relaxations in vulcanized styrene butadiene rubber, SBR. A cure system based on sulphur and TBBS (N-t-butyl-2-benzothiazole sulfenamide) was used in the formulation of several compounds cured at 433...
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2009
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00218995_v113_n4_p2361_Ghilarducci http://hdl.handle.net/20.500.12110/paper_00218995_v113_n4_p2361_Ghilarducci |
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paper:paper_00218995_v113_n4_p2361_Ghilarducci2023-06-08T14:42:57Z About the activation energies of the main and secondary relaxations in cured styrene butadiene rubber Marzocca, Angel José Activation energy Arelaxation B-relaxation Crosslinks Styrene butadiene rubber Arelaxation B-relaxation Benzothiazole Cis-trans Isomerization Conformational change Cross-link densities Crosslinks Cu-Re system Loss tangent Network structures Phenyl group Phenyl rings Polysulphide Secondary relaxations Segmental mode Styrene butadiene rubber Sulfenamide Wide frequency range Butadiene Curing Elastic waves Glass transition Internal friction Isomerization Polysulfides Rotation Rubber Styrene Sulfur Vulcanization Activation energy copolymer cross linking curing (chemistry) friction polysulfide relaxing synthetic rubber This article studies the influence of the network structure on the activation energies of the a and b relaxations in vulcanized styrene butadiene rubber, SBR. A cure system based on sulphur and TBBS (N-t-butyl-2-benzothiazole sulfenamide) was used in the formulation of several compounds cured at 433 K. The activation energies were evaluated from internal friction (loss tangent) data of the compounds using an automated subresonant forced pendulum in a wide frequency range and between 80 K and 273 K. The internal friction data of the samples reveal two transitions, α and β, characterized by the temperatures Tα and Tβ, due to the glass transition and the phenyl group rotation of the copolymer, respectively. Although Tα increases at higher crosslink density, it shows also a dependence with the amount of polysulphide and monosulphide linkages present in the samples. The highest activation energy for this process is obtained for the samples with high crosslink density and 30% of monosulphides in this structure. In the case of the β-relaxation, there is a pronounced change in the activation energy between the uncured and the cured samples. The type of structure formed during vulcanization has an important effect in the activation energy of the segmental mode-process. In the case of the β-process, the cis-trans isomerization that takes place during vulcanization in the butadiene part of the SBR, might be the cause of conformational changes in the surrounding of the phenyl rings that affect the energy barrier associated to the phenyl rotation. © 2009 Wiley Periodicals, Inc. Fil:Marzocca, A.J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00218995_v113_n4_p2361_Ghilarducci http://hdl.handle.net/20.500.12110/paper_00218995_v113_n4_p2361_Ghilarducci |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Activation energy Arelaxation B-relaxation Crosslinks Styrene butadiene rubber Arelaxation B-relaxation Benzothiazole Cis-trans Isomerization Conformational change Cross-link densities Crosslinks Cu-Re system Loss tangent Network structures Phenyl group Phenyl rings Polysulphide Secondary relaxations Segmental mode Styrene butadiene rubber Sulfenamide Wide frequency range Butadiene Curing Elastic waves Glass transition Internal friction Isomerization Polysulfides Rotation Rubber Styrene Sulfur Vulcanization Activation energy copolymer cross linking curing (chemistry) friction polysulfide relaxing synthetic rubber |
| spellingShingle |
Activation energy Arelaxation B-relaxation Crosslinks Styrene butadiene rubber Arelaxation B-relaxation Benzothiazole Cis-trans Isomerization Conformational change Cross-link densities Crosslinks Cu-Re system Loss tangent Network structures Phenyl group Phenyl rings Polysulphide Secondary relaxations Segmental mode Styrene butadiene rubber Sulfenamide Wide frequency range Butadiene Curing Elastic waves Glass transition Internal friction Isomerization Polysulfides Rotation Rubber Styrene Sulfur Vulcanization Activation energy copolymer cross linking curing (chemistry) friction polysulfide relaxing synthetic rubber Marzocca, Angel José About the activation energies of the main and secondary relaxations in cured styrene butadiene rubber |
| topic_facet |
Activation energy Arelaxation B-relaxation Crosslinks Styrene butadiene rubber Arelaxation B-relaxation Benzothiazole Cis-trans Isomerization Conformational change Cross-link densities Crosslinks Cu-Re system Loss tangent Network structures Phenyl group Phenyl rings Polysulphide Secondary relaxations Segmental mode Styrene butadiene rubber Sulfenamide Wide frequency range Butadiene Curing Elastic waves Glass transition Internal friction Isomerization Polysulfides Rotation Rubber Styrene Sulfur Vulcanization Activation energy copolymer cross linking curing (chemistry) friction polysulfide relaxing synthetic rubber |
| description |
This article studies the influence of the network structure on the activation energies of the a and b relaxations in vulcanized styrene butadiene rubber, SBR. A cure system based on sulphur and TBBS (N-t-butyl-2-benzothiazole sulfenamide) was used in the formulation of several compounds cured at 433 K. The activation energies were evaluated from internal friction (loss tangent) data of the compounds using an automated subresonant forced pendulum in a wide frequency range and between 80 K and 273 K. The internal friction data of the samples reveal two transitions, α and β, characterized by the temperatures Tα and Tβ, due to the glass transition and the phenyl group rotation of the copolymer, respectively. Although Tα increases at higher crosslink density, it shows also a dependence with the amount of polysulphide and monosulphide linkages present in the samples. The highest activation energy for this process is obtained for the samples with high crosslink density and 30% of monosulphides in this structure. In the case of the β-relaxation, there is a pronounced change in the activation energy between the uncured and the cured samples. The type of structure formed during vulcanization has an important effect in the activation energy of the segmental mode-process. In the case of the β-process, the cis-trans isomerization that takes place during vulcanization in the butadiene part of the SBR, might be the cause of conformational changes in the surrounding of the phenyl rings that affect the energy barrier associated to the phenyl rotation. © 2009 Wiley Periodicals, Inc. |
| author |
Marzocca, Angel José |
| author_facet |
Marzocca, Angel José |
| author_sort |
Marzocca, Angel José |
| title |
About the activation energies of the main and secondary relaxations in cured styrene butadiene rubber |
| title_short |
About the activation energies of the main and secondary relaxations in cured styrene butadiene rubber |
| title_full |
About the activation energies of the main and secondary relaxations in cured styrene butadiene rubber |
| title_fullStr |
About the activation energies of the main and secondary relaxations in cured styrene butadiene rubber |
| title_full_unstemmed |
About the activation energies of the main and secondary relaxations in cured styrene butadiene rubber |
| title_sort |
about the activation energies of the main and secondary relaxations in cured styrene butadiene rubber |
| publishDate |
2009 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00218995_v113_n4_p2361_Ghilarducci http://hdl.handle.net/20.500.12110/paper_00218995_v113_n4_p2361_Ghilarducci |
| work_keys_str_mv |
AT marzoccaangeljose abouttheactivationenergiesofthemainandsecondaryrelaxationsincuredstyrenebutadienerubber |
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