Synthesis of ZnO/Al2O3 from Bohemite via the Impregnation Method and Its Potential as an Activator in Rubber Vulcanization

Thi Thuong Nghiem1, Minh Tien Nguyen1, Hoang Trung Nguyen1, Han Long Nguyen1,
1 Hanoi University of Science and Technology, Ha Noi, Vietnam

Main Article Content

Abstract

The study synthesized and investigated ZnO/Al2O3 composites as potential activators for rubber vulcanization. Al2O3 was initially prepared from boehmite, followed by ZnO deposition via wet impregnation with varying Zn(NO3)2 solution concentrations. This approach yielded a series of composite 10%, 15%, 20%, 25%, 30%, 35%, and 40% ZnO. Comprehensive characterization was conducted using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, particle size distribution, and scanning electron miscroscopy (SEM). XRD analysis confirmed the formation of g-Al2O3 and the deposition of nano-sized ZnO onto the Al2O3 surface. SEM examination demonstrated that the porous structure of Al2O3 was preserved, particularly in the in 20% ZnO/Al2O3 sample, which was therefore was selected for the natural rubber (NR) vulcanization study. The NR compound containing 10 phr of 20% ZnO/Al2O3 exhibited a steady torque increase over time, with an extended optimal cure time compared to compounds containing conventional ZnO (2 phr) and Al2O3 (8 phr) individually and their physical mixture. Despite the longer cure time, this formulation achieved superior tensile strength and elongation at break. These improvements are attributed to the synergistic effects between ZnO and Al2O3, where ZnO promotes crosslink formation while Al2O3 helps suppress the overcuring typically caused by ZnO.

Article Details

References

[1] S. Sahoo, S. Kar, A. Ganguly, M. Maiti, A. K. Bhowmick, Synthetic zinc oxide nanoparticles as curing agent for polychloroprene, Polymers and Polymer Composites, vol. 16, iss. 3, pp. 193–198, 2008. https://doi.org/10.1177/096739110801600304
[2] S. Sahoo, M. Maiti, A. Ganguly, J.J.George, A. K. Bhowmick, Effect of zinc oxide nanoparticles as cure activator on the properties of natural rubber and nitrile rubber, Journal of Applied Polymer Science, vol. 105, iss. 4, pp. 2407–2415, May 2007. https://doi.org/10.1002/app.26296
[3] S. Sahoo, A. K. Bhowmick, Influence of ZnO nanoparticles on the cure characteristics and mechanical properties of carboxylated nitrile rubber, Journal of Applied Polymer Science, vol. 106, iss. 5, pp. 3077–3083, Aug. 2007. https://doi.org/10.1002/app.24832
[4] B. Panampilly and S. Thomas, Nano ZnO as cure activator and reinforcing filler in natural rubber, Polymer Engineering and Science, vol. 53, iss. 6, pp. 1337–1346, Jun. 2013. https://doi.org/10.1002/pen.23383
[5] X. Qin, H. Xu, G. Zhang, J. Wang, Z. Wang, Y. Zhao, Z. Wang, T. Tan, M. R. Bockstaller, L. Zhang, and K. Matyjaszewski, Enhancing the performance of rubber with nano ZnO as activators, ACS Applied Materials and Interfaces, vol. 12, iss. 42, pp. 48007–48015, Oct. 2020. https://doi.org/10.1021/acsami.0c15114
[6]K. Roy, M. N. Alam, S. K. Mandal, and S. C. Debnath, Surface modification of sol–gel derived nano zinc oxide (ZnO) and the study of its effect on the properties of styrene–butadiene rubber (SBR) nanocomposites, Journal of Nanostructure Chemistry, vol. 4, Sep. 2014, Art. no. 133. https://doi.org/10.1007/s40097-014-0127-9
[7] M. N. Alam, V. Kumar, and S. S. Park, Advances in rubber compounds using ZnO and MgO as co-cure activators, Polymers, vol. 14, Dec. 2022, Art. no. 5289. https://doi.org/10.3390/polym14235289
[8] M. Feldstein, P. Orlovsky, and B. Dogadkin, The role of metal oxides as activators of vulcanization, Rubber Chemistry and Technology, vol. 31, iss. 3, pp. 526–538, Jul. 1958. https://doi.org/10.5254/1.3542304
[9] W. Ahmad, U. Mehmood, A. Al-Ahmed, F. A. Al-Sulaiman, M. Z. Aslam, M. S. Kamal, and R. A. Shawabkeh, Synthesis of zinc oxide/titanium dioxide (ZnO/TiO2) nanocomposites by wet incipient wetness impregnation method and preparation of ZnO/TiO2 paste using poly(vinylpyrrolidone) for efficient dye-sensitized solar cells, Electrochimica Acta, vol. 222, pp. 473–480, Dec. 2016. https://doi.org/10.1016/j.electacta.2016.10.200
[10] S. Das and C. Vimal, An overview of the synthesis of CuO-ZnO nanocomposite for environmental and other applications, Nanotechnology Reviews, vol. 7, iss. 3, pp. 267–282, Apr. 2018. https://doi.org/10.1515/ntrev-2017-0144
[11] H. Tehubijuluw, R. Subagyo, Y. Kusumawati, and D. Prasetyoko, The impregnation of ZnO onto ZSM-5 derived from red mud for photocatalytic degradation of methylene blue, Sustainable Environment Research, vol. 32, Jan. 2022, Art. no. 4. https://doi.org/10.1186/s42834-021-00113-8
[12] N. Hidayah, M. Mustapha, H. Ismail, and M. Kamarol, Linear low-density polyethylene/silicone rubber nanocomposites: optimization of parameters and effect on electrical properties, Journal of Elastomers and Plastics, vol. 50, iss. 1, pp. 36–57, Apr. 2017. https://doi.org/10.1177/0095244317704983
[13] J. F. Fu, L. Y. Chen, H. Yang, Q. D. Zhong, L. Y. Shi, W. Deng, X. Dong, Y. Chen, and G. Z. Zhao, Mechanical properties, chemical and aging resistance of natural rubber filled with nano Al2O3, Polymer Composites, vol. 33, no. 3, pp. 404–411, Feb. 2012.
https://doi.org/10.1002/pc.22162
[14] Yang, Jing, Frost, L. Ray, Synthesis and Characterization of Boehmite Nanofibers, Research Letters in Inorganic Chemistry, vol. 2008, iss. 1, Oct. 2008, Art. no. 602198. https://doi.org/10.1155/2008/602198