Abstract
The engagement of waste tires rubber as source of raw materials for different applications can be a partial solution to the great environmental problems caused by these products. In this study, waste tire rubber was devulcanized using both mechano–chemical and microwave methods. This process was achieved using different concentrations of 2-mercapto benzothiazole disulfide (MBTS) and tetramethylthiuram disulfide (TMTD) as a devulcanizing agent and different microwave devulcanizing times. The optimum content of both MBTS, TMTD and suitable microwave treatment time to make continuous film were noted. The devulcanized waste rubber was then added, at different concentrations, to virgin styrene–butadiene rubber (SBR). The thermal properties and dynamic mechanical behaviors were investigated for all blends. The thermal analysis proved that natural and styrene butadiene rubber are the main two constituents of the waste tire rubber utilized in this study. The mechanical behavior of the SBR blends remarkably improved by using 20 phr waste rubber (WR) devulcanized by 2 phr MBTS and by exposure for 2.2 min to microwaves. Storage modulus, tearing strength and tension set behaviors notably improved for all SBR/WR blends by irradiating with gamma ionizing radiation with a dose of 100 kGy and further improvement could be attained by increasing the dose up to 200 kGy.
Funding source: Academy of Scientific Research
Award Identifier / Grant number: 501100002349
Author contribution: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
Research funding: The authors would like to thank the Academy of Scientific Research, Cairo, Egypt which financially supported this work as part of project no.1439.
Competing interests: The authors declare no conflicts of interest regarding this article.
References
1. Ganjian, E., Khorami, M., Maghsoudi, A. A. Scrap-tyre-rubber replacement for aggregate and filler in concrete. Construct. Build. Mater. 2009, 23, 1828–1836; https://doi.org/10.1016/j.conbuildmat.2008.09.020.Search in Google Scholar
2. Manufacturer’s Association RubberUS Scrap Tire Markets 2003 Edition; Rubber Manufacturer’s Association: Washington (DC), 2004.Search in Google Scholar
3. Dhir, R. K., Limbachiya, M. C., Paine, K. A. Recycling and Reuse of Used Tyres; Thomas Telford Publishing–Thomas Telford Ltd: London, 2001.10.1680/rarout.29958Search in Google Scholar
4. Shulman, V. L. Introduction to Tire Recycling; Europian Tire Recycling Association (ETRA): Paris, France, 2008.Search in Google Scholar
5. ASTM Special Technical Publication, N184A, Glossary of terms relating to rubber technology (V. 29), American Society for testing materials: PA, USA, 1916.Search in Google Scholar
6. Zanchet, A., Carli, L. N., Giovanela, M., Brandalise, R. N., Crespo, J. S. Use of styrene butadiene rubber industrial waste devulcanized by microwave in rubber composites for automotive application materials. Mater. Des. 2012, 39, 437–443; https://doi.org/10.1016/j.matdes.2012.03.014.Search in Google Scholar
7. Hirayama, D., Saron, C. Chemical modifications in styrene–butadiene rubber after microwave devulcanization. Ind. Eng. Chem. Res. 2012, 51, 3975–3980; https://doi.org/10.1021/ie202077g.Search in Google Scholar
8. Haque, K. E. Microwave energy for mineral treatment processes–a brief review. Int. J. Miner. Process. 1999, 57, 1–24; https://doi.org/10.1016/s0301-7516(99)00009-5.Search in Google Scholar
9. Jana, G. K., Das, C. K. Recycling natural rubber vulcanizates through mechanochemical devulcanization. Macromol. Res. 2005, 13, 30–38; https://doi.org/10.1007/bf03219012.Search in Google Scholar
10. Jana, G. K., Mahaling, R. N., Rath, T., Kozlowski, A., Das, C. K. Mechano-chemical recycling of sulfur cured natural rubber. Polymery 2007, 52, 131–136; https://doi.org/10.14314/polimery.2007.131.Search in Google Scholar
11. Sabzekar, M., Chenar, M. P., Mortazavi, S. M., Kariminejad, M., Asadi, S., Zohuri, G. Influence of process variables on chemical devulcanization of sulfur-cured natural rubber. Polym. Degrad. Stabil. 2015, 118, 88–95; https://doi.org/10.1016/j.polymdegradstab.2015.04.013.Search in Google Scholar
12. Chapiro, A. Radiation induced polymerization. Radiat. Phys. Chem. 1979, 14, 101–106; https://doi.org/10.1016/0146-5724(79)90015-3.Search in Google Scholar
13. Singh, R., Chandra, R. Ageing of butyl rubber against UV irradiation. Polym. Photochem. 1982, 2, 257–267; https://doi.org/10.1016/0144-2880(82)90019-7.Search in Google Scholar
14. AbouZeid, M. M., Rabie, S. T., Nada, A. A., Khalil, A. M., Hila, R. H. Effect of gamma irradiation of ethylene propylene dieneterpolymer rubber composite. Nuclear Insttrum. Math. Phys. 2008, 266, 111–116; https://doi.org/10.1016/j.nimb.2007.10.037.Search in Google Scholar
15. Hacioğlu, F., Özdemir, T., Çavdar, S., Usanmaz, A. Possible use of EPDM in radioactive disposal. Long term low dose rate and short high dose rate irradiation in aquatic and atmospheric environment. Radiat. Phys. Chem. 2013, 83, 122–130; https://doi.org/10.1016/j.radphyschem.2012.10.011.Search in Google Scholar
16. Özdemir, T. Gamma irradiation degradation/modification of 5-ethylidene 2- norbornene depending on EBN-based ethylene propylene diene rubber (EPDM) depending on type/content of peroxides used in vulcanization. Radiat. Phys. Chem. 2008, 77, 787–793; https://doi.org/10.1016/j.radphyschem.2007.12.010.Search in Google Scholar
17. El-Nemr, K., Raslan, H., Ali, M., Hasan, M. Innovative γ rays irradiated styrene butadiene rubber/reclaimed waste tire rubber blends: a comparative study using mechano-chemical and microwave devulcanizing methods. Pol. Eng. 2020, 40, 267–277; https://doi.org/10.1515/polyeng-2019-0307.Search in Google Scholar
18. Horowitz, J. C., Metzger, G. A new analysis of thermogravimetric traces. Anal. Chem. 1963, 35, 1464–146; https://doi.org/10.1021/ac60203a013.Search in Google Scholar
19. Yashin, V., Isayev, A. The effect of polydispersity on structure of ultrasonically treated rubbers. Polymer 2004, 45, 6083–6094; https://doi.org/10.1016/j.polymer.2004.06.029.Search in Google Scholar
20. Karger-Kocsis, J., Meszaros, L., Barany, T. Ground tyre rubber (GTR) in thermoplastics, thermosets, and rubbers. J. Mater. Sci. 2013, 48, 1–38; https://doi.org/10.1007/s10853-012-6564-2.Search in Google Scholar
21. Kumnuantip, C., Sombatsompop, N. Dynamic mechanical properties and swelling behaviour of NR/reclaimed rubber blends. Mater. Lett. 2003, 57, 3167–3174; https://doi.org/10.1016/s0167-577x(03)00019-3.Search in Google Scholar
22. Baboo, M., Sharma, K., Saxena, N. S., Kumar, M. Thermomechanical and tensile properties of gamma-ray irradiated blends of cis-polyisoprene and trans-polyisoprene. Polym. Eng. Sci. 2013, 53, 443–451; https://doi.org/10.1002/pen.23271.Search in Google Scholar
23. Choi, S., Son, C. E. Influence of silane coupling agent on bound rubber formation of NR/SBR blend compounds reinforced with carbon black. Polym. Bull. 2016, 73, 453–3464; https://doi.org/10.1007/s00289-016-1666-7.Search in Google Scholar
24. Waki, D. A., da Silva, M. L., Scuracchio, C. H. Thermal analysis of ground tire rubber devulcanized by microwave. J. Therm. Anal. Calorim. 2007, 87, 893–897; https://doi.org/10.1007/s10973-005-7419-8.Search in Google Scholar
25. Fernández-Berridi, M. J., González, N., Mugica, A., Bernicot, C. Pyrolysis-FTIR and TGA techniques as tools in the characterization of blends of natural rubber and SBR. Thermochim. Acta 2006, 444, 65–70; https://doi.org/10.1016/j.tca.2006.02.027.Search in Google Scholar
© 2020 Walter de Gruyter GmbH, Berlin/Boston
