Determination And Analog Computation Of Three-Dimensional Solubility Parameters On HNBR

The Hildebrand one-dimensional solubility parameters (8t, with a unit of (J/cm3)1/2) of Therban LT2007, Therban LT2568, Therban3407, Therban3607, Therban3907, Therban4307and Therban5008were determined by the equilibrium swelling method, and the Hansen three-dimensional solubility parameters (δd,δP,δh,δt) of the seven grades of HNBR were calculated with various modes from Hansen software package called Hansen Solubility Parameter in Practice. Besides, the viscometric method and software package were used to determine the Hildebrand solubility parameter of Therban LT2568and Hansen three-dimensional solubility parameters. In addition, we studied the effect of equilibrium swelling tests by35kinds of single solvent and three groups of solvent mixtures on one-dimensional and three-dimensional solubility parameters. The energy differences (Ra) and relative energy differences (RED) between the seven grades of HNBR and the solvents as well as solvent mixtures were calculated by the three-dimensional solubility parameters obtained from equilibrium swelling test, and meanwhile, the swelling ratios of the seven grades of HNBR in the solvents and solvent mixtures were calculated by Flory-Rehner equation and compared with the results of equilibrium swelling experiment. Finally, we investigated the application of Teas two-dimensional solubility graph in selecting solvents or solvent mixtures.The results showed that both of the equilibrium swelling method and viscometric method had obtained the same one-dimensional solubility parameter range of Therban LT2568from18(J/cm3)1/2to21(J/cm3)1/2, then the swelling ratios obtained from the two methods were used as input for Hansen software package to determine the three-dimensional solubility parameters as being (18.4,6.0,4.5,19.9) and (19.9,5.3,5.6,21.3), respectively. The equilibrium swelling method was considered to be reliable due to the selection of solvents, accuracy of the data and the requirement of the input. Besides, the one-dimensional and three-dimensional solubility parameters of the remaining six kinds of HNBR were determined by the equilibrium swelling test and Hansen software package. The results showed that the one-dimensional solubility parameters of the seven grades of HNBR ranged from18(J/cm3)1/2to21(J/cm3)1/2, and the three-dimensional solubility parameters were Therban LT2007:(18.3,5.4,4.4,19.58), Therban3407:(18.0,6.0,4.0,19.39), Therban3607:(18.9,6.5,5.5,20.73), Therban3907:(18.9,7.5,4.9,20.92), Therban4307:(18.9,8.3,5.8,21.44), Therban5008:(18.2,9.6,5.7,21.35). The polarities or oil-resistance (ACN content) of the seven grades of HNBR could be reflected in the three-dimensional solubility parameters instead of one-dimensional solubility parameter, which further indicated the limitation of one-dimensional solubility parameter in practical application and would be displaced by the three-dimensional solubility parameters.The results of equilibrium swelling tests in solvent mixtures showed that the three-dimensional solubility parameters of Therban LT2568could be determined as well by solvent mixtures with some advantages such as only3to5groups of solvent mixtures needed, few kinds of solvents, short experimental cycle and manageable experimental waste. So, to some extent, it could substitute for the equilibrium swelling test of single solvent. Besides, the selection of solvents or solvent mixtures could be conducted by Teas two-dimensional graph.Moreover, the Ra and RED values between HNBR and solvents and solvent mixtures were calculated by the three-dimensional solubility parameters. The results of the correlation between swelling ratios and Ra or RED showed that the swelling ratios of the seven grades of HNBR in solvents and solvent mixtures decreased with increased Ra or RED values, and the curve showed reversed S-shape. The theoretical swelling ratios calculated by Flory-Rehner equation agreed well with the experimental values. Besides, the swelling ratios of the seven grades of HNBR in IRM903and Fuel C were determined by experiments and calculated by Flory-Rehner equation, both of the experimental values and theoretical values fitted well.So, we concluded that the swelling behavior of HNBR in the liquids could be determined by theoretical calculation, which had very extensive application value and great exploitation foreground.