This work reports physical property measurements of binary mixtures of butylbenzene with n-decane, n-dodecane, n-tetradecane, n-hexadecane, or n-heptadecane. Densities and viscosities were measured at temperatures from (293.15 to 373.15) K, and speeds of sound were measured at temperatures from (293.15 to 333.15) K, except for those of n-heptadecane, which were measured starting at 303.15 K. Densities increased with increasing mole fraction of butylbenzene. Excess molar volumes were positive and increased with increasing alkane chain length, except for those of heptadecane which were similar to those of n-hexadecane. Analysis of excess molar volumes using the Prigogine–Flory–Patterson model showed that the interaction term contributed more to excess molar volume than the free volume or P* term. As the mole fraction of butylbenzene increased, speeds of sound increased for n-decane and n-dodecane mixtures but decreased for other alkane mixtures to values below those of both pure components before increasing again. Viscosities decreased as the mole fraction of butylbenzene increased except for those of some n-decane mixtures, which were below those of butylbenzene and n-decane. Viscosity mole fraction data were fit using the three-body McAllister model. Bulk moduli and surface tension increased with increasing mole fraction of butylbenzene, and flash points fell between those of the individual components. These mixtures can be used as surrogates for petroleum-based fuels.

In this work, the properties of mixtures of 1,2,3,4-tetrahydronaphthalene and trans-decahydronaphthalene were measured. Density and viscosity were measured at temperatures ranging from (293.15 to 373.15) K, and speed of sound was measured at temperatures ranging from (293.15 to 333.15) K. For the mixtures, increasing the mole fraction of 1,2,3,4-tetrahydronaphthalene and decreasing the temperature caused increases in density, speed of sound, bulk modulus, flash point, and surface tension. Mixture viscosities were lower than those of either component. Bulk moduli ranged from (1323 to 2092) MPa over (293.15 to 333.15) K. At room temperature, surface tensions ranged from (30.5 to 35.0) mN·m −1 , and flash points ranged from (328.7 to 343.1) K. The density, speed of sound, and bulk modulus of hydrodepolymerized cellulosic diesel (HDCD) can be matched by mixtures of 1,2,3,4-tetrahydronaphthalene and trans-decahydronaphthalene. The flash point and viscosity of HDCD are higher than those of the mixtures, while its surface tension is lower than those of the mixtures. If combustion is more sensitive to density, speed of sound, and flash point and less sensitive to viscosity, flash point, and surface tension, then a surrogate mixture for HDCD could contain 1,2,3,4-tetrahydronaphthalene and trans-decahydronaphthalene.