Using cation exchange resins Amberlyst 15 as catalyst, triisobutene and phenol as raw materials, synthesized branched-chain dodecylphenol. The effects of temperature, time, the amount of catalyst and mole ratio of phenol and olefin on the alkylation were researched. The impacts conditions were optimized by orthogonal experiment.The results show that alkylation of time is 8 h; mole ratio of phenol and olefin is 6; mass fraction of catalyst is 20% ; reaction temperature is 45 ℃, the maximum dodecylphenol yield (47.1%) could be obtained so that the utilization of triisobutene could reach 90.2%, the yield of branched-chain dodecylphenol could up to 50%.

Determine the solubility of methyl chloride in n-hexane and regress experimental data by Peng-Robinson equation of state(EOS).Phase equilibrium equipment with magnetic stirring apparatus was developed and used in mensurating the solubility of methyl chloride in n-hexane at depression. Its high precision was proved by reliability test. The solubilities at 25，30，35，40 ℃ were measured and the averages of Henry constants are 884,959,1 067,1 172 kPa. It is found that the solubility of methyl chloride in n-hexane are decreases with the temperature increased and increases with the pressure increased. The binary parameter calculated by Peng-Robinson EOS is 0.053 4.The calculated and experimental values of equilibrium pressure are compared, the average relative deviation is 0.985%.Peng-Robinson EOS is accurate in regressing and can be used in more researches.