Synthesis of surfactants with Narrow‐range distribution of the polyoxyethylene chain

Abstract

Ethoxylation of alcohols, alkylphenols, and alkylamines has been studied in the presence of a few catalytic systems. Distribution constants were computed. Broad‐range distributed ethoxylates are formed in the presence of NaOH, and the distribution constants increase up to the homologue containing six oxyethylene units. Narrow‐range distributed ethoxylates are formed in the presence of calcium‐based catalysts. It is reflected in the values of the distribution constants because an increase with the growing number of oxyethylene units in successive homologue is not observed.

Ultrafiltration of Micellar Solutions Containing Phenols

“…The surfactant contains 8 -10 carbon atoms in the alkyl group. The oxyethylated methyl dodecano-ates were obtained in the presence of a calcium-based catalyst under the conditions similar to those used for the oxyethylation of alcohols and alkylphenols (21)(22)(23).…”

Produção de etilenoglicóis e derivados por reações catalíticas do óxido de eteno

“…Na reação com os hidroxilados, se as constantes de velocidade de reação aumentarem nas sucessivas etapas (k i > ... > k 1 > k 0 ), uma quantidade maior de oligômeros será formada já no início da etoxilação e, no final, haverá uma grande quantidade de reagente ROH não convertido, mesmo se for utilizada uma razão estequiométrica 1:1 37 . Portanto, para a obtenção de etoxilados de baixa massa molecular, o ideal seria que k 0 tivesse o maior valor possível e que k 1 fosse menor que k 0 , mas igual ou maior que k 2 e assim por diante, ou seja: k 0 > k 1 ≥ k 2 ≥.... ≥ k i .…”

Estimation of polyoxyethylene chain distribution of alcohol and alkylphenol ethoxylates

“…Nonylphenol and alcohols (Lial 125, Lial 145 and hexadecanol) were oxyethylated normally according to the procedures described previously [4,23] where: A= 100 % hexane B = 5 % H20 in 2-propanol…”

“…Narrowing the oxyethylene chain distribution may be obtained either by physically removing the lower homologues (vacuum distillation) or by using acidic catalysts. In recent years, several new catalysts for oxyethylation have been proposed and narrow range oxyethylates have been manufactured without formation of excessive amounts of polyglycols and other undesirable products [1][2][3][4].…”