1,3-디옥산을 함유한 분해성 계면활성제의 합성의 및 계면 특성

Synthesis of Surface Active Properties of Destructible Surfactants with 1,3-Dioxane

In acid-catalyzed acetal cyclization of long aliphatic aldehydes(R=n-C₇H₁₅ ; n-C₉H₁₉ : n-C₁₁H₂₃) with 1,1,1-tris(hydroxymethyl)propane, 2-alkyl-5-hydroxymethyl-5-ethyl-1,3-dioxanes were obtained. The final products, sodium 2-alkyh-5-(sulfonatedpropylethermethyl)-5-ethyl-1, 3-dioxanes, were synthesized successfully in the reaction of three kinds of intermediates with 1, 3-propanesultion in the presence of sodium hydride. These compounds were a new group of destructible surfactants which were readily hydrolyzed and oxidized in natural water reservoirs. Physical properties of these new compounds involved some surface properties such as Krafft point(Kp), critical micelle concentration(cmc), surface tension of aqueous solutions near cmc(γmin), foaming power, emulsion power and hydrolysis properties were determined. The destructible surfactants containing 1, 3-dioxane ring were synthesized to about 85±5.5% yield. The cmc values of the compounds by ring method were assumed to 0.5~5.0×10⁻³mol/L range and surface tensions at cmc were 29.5~33.0dyne/cm respectively at 25℃. The foaming power and foam stability were 170~230mm and 52~135mm respectively at 1×10⁻²mol/L, foam was occurred rarely below 1×10⁻³mol/L. The emulsion property of liquid paraffin was better than that of soybean oil. For hydrolysis property with ph and time, these compounds were decomposed within about 200minutes at ph1~2. Hopefully these compounds are expected to be a good O/W emulsifier that have decomposability in acid and may be used in the process which do not need foaming.