Influence of enzymatic devulcanization process conditions on the tensile strength of revulcanized rubber
Rubber based product has properties very different from the viscous latex of the rubber tree, Hevea brasiliensis. The properties of rubber latex are usually changed to enable it be used in production of many rubbers based products such as tires, hoses, and etc. To strengthen it, the rubber undergo...
| Main Authors: | , , |
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| Format: | Conference or Workshop Item |
| Language: | English |
| Published: |
Kulliyah of Engineering, International Islamic University Malaysia
2016
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| Subjects: | |
| Online Access: | http://irep.iium.edu.my/51550/ http://irep.iium.edu.my/51550/ http://irep.iium.edu.my/51550/1/51550.pdf |
| Summary: | Rubber based product has properties very different from the viscous latex of the rubber tree, Hevea
brasiliensis. The properties of rubber latex are usually changed to enable it be used in production of many
rubbers based products such as tires, hoses, and etc. To strengthen it, the rubber undergoes vulcanization
process where the addition of sulfur and heating the mixture under pressure is done which results in the
formation of sulfur-bridges between the hydrocarbon chains. It makes an economic sense to recycle spent
rubber products. Prior to recycling, surface devulcanization of rubber is vital to produce the acceptable
reprocessed product. Devulcanization is basically a process that cleaved the monosulfidic, disulfidic or
polysulfidic of vulcanized rubber. The tensile strength of the new material is of paramount important. In this
study, process optimization for the enzymatic devulcanization of rubber was performed. Design of
Experiment and analysis was conducted using Design Expert® (Version 6.0.8) software, with the tensile
strength as the response. Results showed that both factors tested, time of incubation and rubber
concentration contributed significantly towards the strength of rubber products. Data shows that setting the
incubation time for 4 hours with 4% w/v rubber in the incubation media results in the highest tensile strength
of 10.7 MPa, an increase of 67% from the untreated control. In conclusion, the process conditions of the
enzymatic devulcanization of used rubber product have been successfully optimized using tetrathionate
hydrolase rich media, produced by Thiobacillus ferrooxidans. This information is important to improve
enzymatic devulcanization method and finally to increase the percentage of rubber recycling. |
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