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Best Practice for De-Vulcanization of Waste Passenger Car Tire Rubber Granulate Using 2-2(′)-dibenzamidodiphenyldisulfide as De-Vulcanization Agent in a Twin-Screw Extruder

De-vulcanization of rubber has been shown to be a viable process to reuse this valuable material. The purpose of the de-vulcanization is to release the crosslinked nature of the highly elastic tire rubber granulate. For present day passenger car tires containing the synthetic rubbers Styrene-Butadie...

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Autores principales: van Hoek, Hans, Noordermeer, Jacques, Heideman, Geert, Blume, Anke, Dierkes, Wilma
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8038231/
https://www.ncbi.nlm.nih.gov/pubmed/33918356
http://dx.doi.org/10.3390/polym13071139
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author van Hoek, Hans
Noordermeer, Jacques
Heideman, Geert
Blume, Anke
Dierkes, Wilma
author_facet van Hoek, Hans
Noordermeer, Jacques
Heideman, Geert
Blume, Anke
Dierkes, Wilma
author_sort van Hoek, Hans
collection PubMed
description De-vulcanization of rubber has been shown to be a viable process to reuse this valuable material. The purpose of the de-vulcanization is to release the crosslinked nature of the highly elastic tire rubber granulate. For present day passenger car tires containing the synthetic rubbers Styrene-Butadiene Rubber (SBR) and Butadiene Rubber (BR) and a high amount of silica as reinforcing filler, producing high quality devulcanizate is a major challenge. In previous research a thermo-chemical mechanical approach was developed, using a twin-screw extruder and diphenyldisulfide (DPDS) as de-vulcanization agent.The screw configuration was designed for low shear in order to protect the polymers from chain scission, or uncontrolled spontaneuous recombination which is the largest problem involved in de-vulcanization of passenger car tire rubber. Because of disadvantages of DPDS for commercial use, 2-2 [Formula: see text]-dibenzamidodiphenyldisulfide (DBD) was used in the present study. Due to its high melting point of 140 °C the twin-screw extruder process needed to be redesigned. Subsequent milling of the devulcanizate at 60 °C with a narrow gap-width between the mill rolls greatly improved the quality of the devulcanizate in terms of coherence and tensile properties after renewed vulcanization. As the composition of passenger car tire granulate is very complex, the usefulness of the Horikx-Verbruggen analysis as optimization parameter for the de-vulcanization process was limited. Instead, stress-strain properties of re-vulcanized de-vulcanizates were used. The capacity of the twin-screw extruder was limited by the required residence time, implying a low screw speed. A best tensile strength of 8 MPa at a strain at break of 160% of the unblended renewed vulcanizate was found under optimal conditions.
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spelling pubmed-80382312021-04-12 Best Practice for De-Vulcanization of Waste Passenger Car Tire Rubber Granulate Using 2-2(′)-dibenzamidodiphenyldisulfide as De-Vulcanization Agent in a Twin-Screw Extruder van Hoek, Hans Noordermeer, Jacques Heideman, Geert Blume, Anke Dierkes, Wilma Polymers (Basel) Article De-vulcanization of rubber has been shown to be a viable process to reuse this valuable material. The purpose of the de-vulcanization is to release the crosslinked nature of the highly elastic tire rubber granulate. For present day passenger car tires containing the synthetic rubbers Styrene-Butadiene Rubber (SBR) and Butadiene Rubber (BR) and a high amount of silica as reinforcing filler, producing high quality devulcanizate is a major challenge. In previous research a thermo-chemical mechanical approach was developed, using a twin-screw extruder and diphenyldisulfide (DPDS) as de-vulcanization agent.The screw configuration was designed for low shear in order to protect the polymers from chain scission, or uncontrolled spontaneuous recombination which is the largest problem involved in de-vulcanization of passenger car tire rubber. Because of disadvantages of DPDS for commercial use, 2-2 [Formula: see text]-dibenzamidodiphenyldisulfide (DBD) was used in the present study. Due to its high melting point of 140 °C the twin-screw extruder process needed to be redesigned. Subsequent milling of the devulcanizate at 60 °C with a narrow gap-width between the mill rolls greatly improved the quality of the devulcanizate in terms of coherence and tensile properties after renewed vulcanization. As the composition of passenger car tire granulate is very complex, the usefulness of the Horikx-Verbruggen analysis as optimization parameter for the de-vulcanization process was limited. Instead, stress-strain properties of re-vulcanized de-vulcanizates were used. The capacity of the twin-screw extruder was limited by the required residence time, implying a low screw speed. A best tensile strength of 8 MPa at a strain at break of 160% of the unblended renewed vulcanizate was found under optimal conditions. MDPI 2021-04-02 /pmc/articles/PMC8038231/ /pubmed/33918356 http://dx.doi.org/10.3390/polym13071139 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
van Hoek, Hans
Noordermeer, Jacques
Heideman, Geert
Blume, Anke
Dierkes, Wilma
Best Practice for De-Vulcanization of Waste Passenger Car Tire Rubber Granulate Using 2-2(′)-dibenzamidodiphenyldisulfide as De-Vulcanization Agent in a Twin-Screw Extruder
title Best Practice for De-Vulcanization of Waste Passenger Car Tire Rubber Granulate Using 2-2(′)-dibenzamidodiphenyldisulfide as De-Vulcanization Agent in a Twin-Screw Extruder
title_full Best Practice for De-Vulcanization of Waste Passenger Car Tire Rubber Granulate Using 2-2(′)-dibenzamidodiphenyldisulfide as De-Vulcanization Agent in a Twin-Screw Extruder
title_fullStr Best Practice for De-Vulcanization of Waste Passenger Car Tire Rubber Granulate Using 2-2(′)-dibenzamidodiphenyldisulfide as De-Vulcanization Agent in a Twin-Screw Extruder
title_full_unstemmed Best Practice for De-Vulcanization of Waste Passenger Car Tire Rubber Granulate Using 2-2(′)-dibenzamidodiphenyldisulfide as De-Vulcanization Agent in a Twin-Screw Extruder
title_short Best Practice for De-Vulcanization of Waste Passenger Car Tire Rubber Granulate Using 2-2(′)-dibenzamidodiphenyldisulfide as De-Vulcanization Agent in a Twin-Screw Extruder
title_sort best practice for de-vulcanization of waste passenger car tire rubber granulate using 2-2(′)-dibenzamidodiphenyldisulfide as de-vulcanization agent in a twin-screw extruder
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8038231/
https://www.ncbi.nlm.nih.gov/pubmed/33918356
http://dx.doi.org/10.3390/polym13071139
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