Study on the Synthesis and Performance of Alkyl Fatty Alcohol Ether Sulfonate with Three Short Branch Chains

Abstract

To address the limitations of conventional surfactants in high-temperature and high-salinity reservoir environments, a novel surfactant, iso-tridecanol polyoxyethylene ether sulfonate, was successfully synthesized using iso-tridecanol polyoxyethylene ether as the raw material. The synthesis was achieved through an olefin addition process, involving an allylation reaction followed by a sulfonation reaction. Key factors such as catalyst concentration, reaction temperature, reaction time, and reactant molar ratios were systematically investigated to evaluate their impact on both the allylation reaction and the sulfonation reaction. Based on single-factor experiments results, an orthogonal experimental design was used to optimize the synthesis conditions. The optimal conditions for the allylation reaction were determined as follows: reaction temperature of 100°C, reaction time of 6 h, catalyst concentration of 8%, and a molar ratio of n (iso-tridecanol polyoxyethylene ether): n (chloropropylene) = 1:1.5. For the sulfonation reaction, the optimal conditions were determined as follows: reaction temperature of 120°C, reaction time of 8 h, catalyst concentration of 8%, and a molar ratio of n (allyl ether): n (NaHSO₃) = 1:1.8. The structures of both the intermediates and final products were characterized by infrared spectroscopy and nuclear magnetic resonance. Performance testing revealed that the dynamic interfacial tension of A13ESO7 sulfonate decreased over time and eventually stabilized, reaching an equilibrium value on the order of 10⁻2 mN/m. The surfactant exhibited excellent surface activity and thermal stability at 80°C and 120°C. It also demonstrated remarkable salt resistance, with a new phase appearing until NaCl concentration reached 150 g/L or CaCO₃ concentration reached 15 g/L. The emulsification time increased with the concentration of A13ESO7 surfactant, indicating strong emulsification stability performance. Additionally, as the soaking time increased, the contact angle of the core surface stabilized and eventually decreasing to 52°, demonstrating that the A13ESO7 surfactant effectively reversed the wettability of the core surface from oil-wet to water-wet. Compared to traditional linear chain A12ESO7, the branched structure of A13ESO7 contributes to its enhanced performance.

Department(s)

Geosciences and Geological and Petroleum Engineering

Second Department

Chemical and Biochemical Engineering

Comments

National Natural Science Foundation of China, Grant U22B6005

Keywords and Phrases

Anionic-nonionic surfactant; Iso-tridecanol polyoxyethylene ether sulfonate; Olefin addition method; Synthesis; Temperature- and salt-resistant

International Standard Serial Number (ISSN)

0022-2860

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2025 Elsevier, All rights reserved.

Publication Date

25 Dec 2025

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