Effect of alkyl chain length and number of 2-hydroxyethyl groups on drag reduction behaviors of quaternary ammonium salt-type cationic surfactant solutions

Effect of chemical structure on drag reduction behaviors of quaternary ammo nium salt cationic surfactant solutions in the presence of sodium salicylat e (NaSal) was investigated in terms of 1) alkyl chain length and 2) number of 2-hydroxyethyl groups. From the present investigation, we can draw the f ollowing conclusions; 1) Increasing in alkyl chain length in the quaternary ammonium salt in the presence of NaSal increased the maximum temperature at which drag reduction can be sustained. 2) The presence of the double bond in alkyl chain had a significant effect on lower temperature drag reduction limit. 3) The DR effect of HMODA complexed with NaSal, which was replaced the meth yl groups in TMODA with two 2-hydroxyethyl groups, gave better drag reducti on in the wide temperature range 6-60 degreesC.