Synthesis and Surface Properties of N-Alkyl-N-methylgluconamides and N-Alkyl-N-methyllactobionamides
✍ Scribed by Bogdan Burczyk; Kazimiera A Wilk; Adam Sokołowski; Ludwik Syper
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 88 KB
- Volume
- 240
- Category
- Article
- ISSN
- 0021-9797
No coin nor oath required. For personal study only.
✦ Synopsis
Three series of nonionic N-alkylaldonamides, N-alkyl-Nmethylgluconamides (Cn-MGA, Cn: n-C 10 H 21 , n-C 12 H 25 , n-C 14 H 29 , n-C 16 H 33 , and n-C 18 H 37 ), N-alkyl-N-methyllactobionamides (Cn-MLA, alkyl as above-mentioned), and N-oleyl-N-methylglucon/ lactobionamide, were synthesized in the reaction of an appropriate N-alkyl-N-methylamine with δ-D-glucolactone and lactobionic acid, respectively. Krafft temperatures of aqueous solutions and surface properties of these surfactants at 20 • C, i.e., surface excess concentration, cmc , surface area demand per molecule, A min , efficiency in surface tension reduction, pC 20 , effectiveness in surface tension reduction, cmc , critical micelle concentration, CMC, and CMC/C 20 parameter as well as standard free energies of adsorption, G • ads , and of micellization, G • mic , were determined. It was shown that introduction of the methyl group to the amide nitrogen increased the solubility of the surfactants, which was confirmed by their Krafft temperatures. Lactobionamides are more water soluble than gluconamides. On the other hand, the Cn-MGA surfactants are more surface active than the respective Cn-MLA ones. This observation is based on the determined adsorption and micellization parameters. The presence of one double bond in a hydrocarbon chain as in oleyl-amides increases their hydrophilic character compared with that of saturated C18 derivatives. No distinct differences were observed between the A min values obtained for both series studied, although they differ markedly in the size of the hydrophilic groups.
📜 SIMILAR VOLUMES
The thermal isomerizations of N-[a -(alkylthio)alkyl]-and N-[a -(arylthio)alkyl]benzotriazoles have been investigated under N, atmospheres i ) in toluene, xylene, MeOH, or EtOH, in the presence of acid catalysts and ii) in the absence of solvent. The sulfide isomerization rates depend on the number
Wetting behavior of perfluoroalkylethyl acrylate (FA)/n-alkyl acrylate (AA) copolymers with the various length of side chains of the AAs is discussed from a standpoint of surface molecular mobility. The copolymerization reactivity ratio indicates that these polymers are random copolymers. The surfac