| The one-dimensional solubility parameters (δt, with a unit of (J/cm3)1/2) of sevengrades of EVM and four grades of EP(D)M were calculated by Small and Fedors groupcontribution methods in this paper. And the range of their one-dimensional solubilityparameters were determined by the equilibrium swelling method.Beaucase thelimitation of one-dimensional solubility parameter, we calculated the Hansenthree-dimensional solubility parameters (δd, δp, δh, δt) of the seven grades of EVM andfour grades of EP(D)M using Hansen software. Besides, the influence of mixed solventfor swelling behavior of EVM were studied. The energy differences (Ra) and relativeenergy differences (RED) between EP(D)M and the solvents were calculated as well asEVM by the three-dimensional solubility parameters obtained from equilibriumswelling test and the analog calculation. Meanwhile, the Flory-Huggins parameter ofthe EVM and EP(D)M with the solvents were calculated using the Flory theory.The results showed that using the Group contribution method the range of theone-dimensional solubility parameter of EVM is between17.80(J/cm3)1/2and21.00(J/cm3)1/2, the range of EP(D)M is between16.20(J/cm3)1/2and17.50(J/cm3)1/2. Andthe solubility parameters of them calculated by Small method were smaller than thoseof Fedors method.From the equilibrium swelling test, the range of one-dimensionalsolubility parameter of seven grades of EVM is between17.50(J/cm3)1/2and22.00(J/cm3)1/2, meanwhile, with the increase of VA%, the solubility parameter of EVMincreased. The range of one-dimensional solubility parameter of four grades of EP(D)M were near17.00(J/cm3)1/2, which showed that the result from equilibriumswelling test agreed well with Fedors method.The three-dimensional solubility parameters of EVM and EP(D)M werecalculated by Hansen software. The three-dimensional solubility parameters of EVMwere Levapren400:(17.6,3.8,3.4,18.32), Levapren450:(17.6,3.8,3.6,18.36),Levapren500:(17.6,4.0,4.0,18.49), Levapren600:(17.7,4.5,4.5,18.81), Levapren700:(18.0,4.9,5.1,19.34), Levapren800:(18.2,5.5,6.1,19.97), Levapren900:(18.4,6.4,6.2,20.44). The result showed that, the dispersion, polar and hydrogen solubilityparameters were increased with the increasing of VA%contect, but the VA contectmainly influenced the polar and hydrogen solubility parameters. Thethree-dimensionalsolubility parameters of EP(D)M were Keltan2070P:(17.1,2.3,0,17.25), Keltan3050:(16.8,2.7,0,17.02), Keltan6750:(16.9,2.3,0,17.06), Keltan8570:(17.1,2.4,0,17.27), which showed that, for EP(D)M that with same ENBcontect reduced the ethylene contect, its dispersion solubility parameter decreased,while polar solubility parameter increased. For EP(D)M that with same ethylenecontect, the one which contained the third monomer ENB had higher dispersionsolubility parameter and lower polar solubility parameter.This paper had studied the swelling behavior of Levapren450and Levapren800in mixed solvents. The results showed that the solubility parameter of rubber could betestes using mixed solvents. Determination of the solubility parameters of rubbers bymixed solvents had some advantages such as short experimental cycle less solvent typeand manageable experimental waste. To a certain extent, it could substitute for thecomplex single solvent.Moreover, the Raand RED values between rubber and solvents were calculatedby the three-dimensional solubility parameters. The results of the correlation betweenswelling ratios and Raor RED showed that the swelling ratios of the EVM andEP(D)M in solvents decreased with increased Raor RED values. The results ofswelling ratio of EVM in Fuel C showed that the theoretical calculation value wasconsistent with the experimental value, so we could predict the swelling behavior ofrubber in the solvents by using Hansen three-dimensional solubility parameters.. |
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