Comparison of Coupling Effectiveness among Amino-, Chloro-, and Mercapto Silanes in Chloroprene Rubber

Abstract:

The present work focuses mainly on the uses of silane coupling agents in chloroprene rubber (CR) reinforced with precipitated silica (PSi). Grafting of organoalkoxysilane onto surfaces of PSi was conducted, and the characteristics of surface-modified PSi were determined by BET technique, light-scattering particle size analysis, DRIFT and ²⁹Si NMR spectroscopy. The 3 types of silane coupling agents used in this work were as follows: 3-aminopropyl triethoxysilane (APTES), 3-chloropropyl triethoxysilane (CPTES) and bis (3-triethoxysilylpropyl) tetrasulfide (TESPT). Processability of compounds and mechanical properties of vulcanizates were then investigated, and compared for the effectiveness of silane coupling agents used in property enhancement. The results reveal that the silane type affects not only the compound processability, but also the vulcanizate mechanical properties. Among 3 silanes, the CPTES and TESPT are capable of reducing the filler-filler interaction to greater extent than the APTES, leading to superior compound processability. Moreover, the amino and mercapto groups of APTES and TESPT, respectively, significantly enhance the mechanical properties of CR vulcanizate more effectively than the chloro groups of CPTES. This might be ascribed to the combined effects of enhanced rubber-filler interaction and improved filler dispersion.

• Periodical: Advanced Materials Research (Volume 747)
• Pages: 530-533
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.747.530
• Online since: August 2013
• Authors: Chomsri Siriwong, Pongdhorn Sea-Oui, Chakrit Sirisinha
• Keywords: Chloroprene Rubber, Reinforcement, Silane Coupling Agent

References

[1] S.J. Park and K.S. Cho, Filler-Filler interactions: influence of silane coupling agent on crosslink density and thermal stability of silica/rubber composites, J. colloid Interface Sci., 267 (2003) 86 – 91.

DOI: 10.1016/s0021-9797(03)00132-2

[2] W. Chonkaew, W. Mingvanish, U. Kungliean, N. Rochanawipart, and W. Brostow, Vulcanization characteristics and dynamic mechanical behavior of natural rubber reinforced with silane modified silica, J. of Nanosci. and Nanotech. 11 (2011).

DOI: 10.1166/jnn.2011.3563

[3] S. de Monredon-Senani, and C. Bonhomme, Covalent grafting of organoalkoxysilanes on silica surfaces in water rich medium as evidenced by 29Si NMR, J. of sol-gel Sci. Tech. 50 (2009) 152 – 157.

DOI: 10.1007/s10971-009-1920-7

[4] L.A.E.M. Reuvekamp, J.W. ten Brinke, P.J. van Swaaij, J.W.M. Noordermeer, Kaut. Gummi Kunstst. 55 (2002) 41.