Premium
The effect of position of ester group on critical micelle concentration of ester‐linked sulfonates
Author(s) -
Hikota Takeshi,
Meguro Kenjiro
Publication year - 1970
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02638869
Subject(s) - methylene , chemistry , alkyl , critical micelle concentration , thermodynamics of micellization , micelle , aqueous solution , medicinal chemistry , sodium , sulfonate , sodium salt , carbon chain , stereochemistry , organic chemistry , inorganic chemistry
The critical micelle concentration (CMC) of sodium alkyl sulfoacetates and β‐sulfopropionates, and sodium salt of 2‐sulfo ethyl ester, 3‐sulfo propyl ester and 4‐sulfo butyl ester of fatty acids have been determined by the electrical conductance of each aqueous solution. The relation between CMC value and number of total methylene groups (N) for the C n * H 2n * + 1 COO(CH 2 ) 3 SO 3 Na and C 9 H 19 COO(CH 2 ) n ** SO 3 Na (n * =9, 10 and 11. n ** =2, 3 and 4) can be formulated as follows.log CMC = − 0.293N + 1.778forC n ∗ H 2 n ∗+ 1COO ( CH 2 )3SO 3 Nalog CMC = − 0.147N + 0.011forC 9 ∗ H 19COO( CH 2 ) n∗ ∗SO 3 NaFrom these equations it was determined that the methylene unit situated between ester and sulfonate groups is equivalent to 0.5 methylene groups in its effect on CMC. For a given number of carbon atoms in the alkyl chain, the log CMC value increased regularly with a change in the ester group away from the terminal position to more central positions in the hydrocabon chain. The two different types of ester‐linkages (RCOO‐and ROCO‐) have no apparent effect on the CMC value.