Polímeros: Ciência e Tecnologia
Polímeros: Ciência e Tecnologia
Original Article

Cross-link density measurement of nitrile rubber vulcanizates using dynamic shear testa

Gustavo Ninho Campos; Ana Carolina Ribeiro Coimbra; Arianne Aparecida da Silva; Elisson Brum Dutra da Rocha; Felipe Nunes Linhares; Cristina Russi Guimarães Furtado; Ana Maria Furtado de Sousa

Downloads: 2
Views: 523


Cross-link density impacts most mechanical properties of rubber, therefore it is necessary to have a method to measure it. The most widely used method is via equilibrium swelling, however, it is time consuming and uses organic solvents. Dynamic Shear Test (DST) can be used to calculate both chemical and physical cross-links in rubber compounds in shorter times than by swelling equilibrium method, and without the use of solvents. In this work, equilibrium swelling using toluene and acetone was used to validate the dynamic shear tests for different nitrile rubber (NBR) compounds. The DST had a good correlation with the swelling equilibrium method using acetone, with a correlation coefficient of ~0,91, validating the use of DST. Moreover, the use of the Modified Guth-Gold equation (instead of Guth-Gold Equation with Medalia correction) also allowed to deduct the effect of carbon black on the cross-link density from the DST.




nitrile rubber, cross-link density, dynamic shear test, swelling equilibrium, solubility parameter


1 Yang, Z., Guo, B., & Zhang, L. (2017). Challenge of rubber/graphene composites aiming at real applications. Rubber Chemistry and Technology, 90(2), 225-237. http://dx.doi.org/10.5254/rct.17.82634.

2 Valentín, J. L., Carretero-González, J., Mora-Barrantes, I., Chassé, W., & Saalwächter, K. (2008). Uncertainties in the determination of cross-link density by equilibrium swelling experiments in natural rubber. Macromolecules, 41(13), 4717-4729. http://dx.doi.org/10.1021/ma8005087.

3 Blume, A., & Kiesewetter, J. (2019). Determination of the crosslink density of tire tread compounds. KGK. 72(9), 33-42. Retrieved in 2022, March 24, from https://www.kgk-rubberpoint.de/wp-content/uploads/2019/09/KGK_09_2019_33-42.pdf

4 Saleesung, T., Reichert, D., Saalwächter, K., & Sirisinha, C. (2015). Correlation of crosslink densities using solid state NMR and conventional techniques in peroxide-crosslinked EPDM rubber. Polymer, 56, 309-317. http://dx.doi.org/10.1016/j.polymer.2014.10.057.

5 Vieyres, A., Pérez-Aparicio, R., Albouy, P.-A., Sanseau, O., Saalwächter, K., Long, D. R., & Sotta, P. (2013). Sulfur-cured natural rubber elastomer networks: correlating cross-link density, chain orientation, and mechanical response by combined techniques. Macromolecules, 46(3), 889-899. http://dx.doi.org/10.1021/ma302563z.

6 Lee, S., Pawlowski, H., & Coran, A. Y. (1994). Method for estimating the chemical crosslink densities of cured natural rubber and styrene-butadiene rubber. Rubber Chemistry and Technology, 67(5), 854-864. http://dx.doi.org/10.5254/1.3538716.

7 Pechurai, W., Sahakaro, K., & Nakason, C. (2009). Influence of phenolic curative on crosslink density and other related properties of dynamically cured NR/HDPE blends. Journal of Applied Polymer Science, 113(2), 1232-1240. http://dx.doi.org/10.1002/app.30036.

8 Silva, V. M., Nunes, R. C. R., & Sousa, A. M. F. (2017). Epoxidized natural rubber and hydrotalcite compounds: rheological and thermal characterization. Polímeros: Ciência e Tecnologia, 27(3), 208-212. http://dx.doi.org/10.1590/0104-1428.03416.

9 Ünügül, T., & Karaağaç, B. (2021). Vulcanization of chlorinated polyethylene / chloroprene rubber compounds at lower temperatures in the presence of reactive silanes. Journal of Applied Polymer Science, 138(23), 50544. http://dx.doi.org/10.1002/app.50544.

10 Fukahori, Y., Hon, A. A., Jha, V., & Busfield, J. J. C. (2013). Modified guth-gold equation for carbon black-filled rubbers. Rubber Chemistry and Technology, 86(2), 218-232. http://dx.doi.org/10.5254/rct.13.87995.

11 Lee, J.-Y., Park, N., Lim, S., Ahn, B., Kim, W., Moon, H., Paik, H.-J., & Kim, W. (2017). Influence of the silanes on the crosslink density and crosslink structure of silica-filled solution styrene butadiene rubber compounds. Composite Interfaces, 24(7), 711-727. http://dx.doi.org/10.1080/09276440.2017.1267524.

12 Kim, D. Y., Park, J. W., Lee, D. Y., & Seo, K. H. (2020). Correlation between the crosslink characteristics and mechanical properties of natural rubber compound via accelerators and reinforcement. Polymers, 12(9), 2020. http://dx.doi.org/10.3390/polym12092020. PMid:32899685.

13 Xu, Q., Majlingova, A., Zachar, M., Jin, C., & Jiang, Y. (2012). Correlation analysis of cone calorimetry test data assessment of the procedure with tests of different polymers. Journal of Thermal Analysis and Calorimetry, 110(1), 65-70. http://dx.doi.org/10.1007/s10973-011-2059-7.

14 Fei, Z., Long, C., Qingyan, P., & Shugao, Z. (2012). Influence of carbon black on crosslink density of natural rubber. Journal of Macromolecular Science, Part B: Physics, 51(6), 1208-1217. http://dx.doi.org/10.1080/00222348.2012.664494.

15 Robertson, C. G., & Hardman, N. J. (2021). Nature of carbon black reinforcement of rubber: perspective on the original polymer nanocomposite. Polymers, 13(4), 538. http://dx.doi.org/10.3390/polym13040538. PMid:33673094.

16 Yadollahi, S., Ramezani, M., Razzaghi-Kashani, M., & Bahramian, A.-R. (2018). Nonlinear viscoelastic dissipation in vulcanizates containing carbon black and silanized silica hybrid fillers. Rubber Chemistry and Technology, 91(3), 537-547. http://dx.doi.org/10.5254/rct.18.82611.

17 Koenig, J. L. (2000). Spectroscopic characterization of the molecular structure of elastomeric networks. Rubber Chemistry and Technology, 73(3), 385-404. http://dx.doi.org/10.5254/1.3547598.

18 Negri, R. B. P., Silva, A. H. M. F. T., Sousa, A. M. F., Silva, A. L. N., & Rocha, E. B. D. (2021). Improved mechanical and rheological behavior of nitrile rubber reinforced with multi-walled carbon nanotubes and carbon black dual-filler system. Materials Today Communications, 26, 101884. http://dx.doi.org/10.1016/j.mtcomm.2020.101884.

19 Rocha, E. B. D., Batista, M. R., Linhares, F. N., Silva, A. L. N., Delpech, M. C., Sousa, A. M. F., & Furtado, C. R. G. (2019). Cyclic uniaxial stress-strain test and rheological behavior of carbon black/metakaolin dual-filler system used in nitrile rubber compounds. Polymer Testing, 77, 105906. http://dx.doi.org/10.1016/j.polymertesting.2019.105906.

20 Fan, R., Zhang, Y., Huang, C., Zhang, Y., Fan, Y., & Sun, K. (2001). Effect of crosslink structures on dynamic mechanical properties of natural rubber vulcanizates under different aging conditions. Journal of Applied Polymer Science, 81(3), 710-718. http://dx.doi.org/10.1002/app.1488.

62c5e65da95395341f0c9b52 polimeros Articles
Links & Downloads

Polímeros: Ciência e Tecnologia

Share this page
Page Sections