关键词: 松香, 胆碱, 表面活性剂, 抑菌活性

Abstract: Choline was reacted with dehydroabietic acid, N-(dehydroabietyl)maleamic acid, acrylopimaric acid and maleopimaric acid, respectively, to prepare four rosinyl choline quaternary ammonium surfactants(Ⅰ₁-Ⅳ₁). And tetramethyl ammonium hydroxide was reacted with the four compounds respectively to prepare four rosinyl quaternary ammonium surfactants without hydroxyl groups (Ⅰ₂-Ⅳ₂). Their structures were characterized by IR, ¹H NMR, ¹³C NMR spectra. Their critical micelle concentration (CMC), surface tension (γ_CMC), emulsifying ability, foaming ability, HLB value and bactericidal activity were evaluated. The results showed that CMC values of Ⅰ₁, Ⅱ₁, Ⅲ₁, Ⅳ₁ were 6.9, 2.0, 3.8 and 8.0 mmol/L, the corresponding γ_CMC values were 37.9, 35.1, 40.0 and 42.4 mN/m. The CMC values of Ⅰ₂, Ⅱ₂, Ⅲ₂, Ⅳ₂ were 9.4, 5.2, 6.2 and 10.0 mmol/L, the corresponding γ_CMC values were 39.7, 39.0, 43.1 and 45.1 mN/m. By comparison, CMC values and γ_CMC of quaternary ammonium salt surfactants with hydroxy groups were smaller than those of quaternary ammonium salt surfactants without hydroxyl groups. It could be seen that the existence of the hydroxyl groups could improve the surface activities of surfactants. HLB values of eight rosin-based quaternary ammonium salts were greater than 18. This showed that they had good hydrophilicity. The foaming ability of Ⅱ₁ was better than the others, and foaming height was 202 mm, and then it turned to 165 mm after 5 min. Ⅲ₁, Ⅲ₂, Ⅳ₁ and Ⅳ₂ exhibited excellent antibacterial activity against Staphyloccocus epidermidis with minimum inhibition concentration of 2 mg/L, and the antibacterial activities were superior to the Bromogeramine and Ampicillin sodium. It showed that the existence of hydroxyl groups did not affect antibacterial activities of rosin-based quaternary ammonium salt.

Key words: rosin, choline, surfactant, antibacterial activity