Abstract:

Dehydroabietol polyoxyethylene（5） ether （DA（EO）₅H） was condensated with epichlorohydrin in the presence of boron fluoride diethyl etherate firstly. Then, dehydroabietyl polyoxyethylene glycidyl ether （DA（EO） ₅GE） was obtained through dehydrochlorination of the condensation product in the presence of NaOH. Finally, DA（EO） ₅GE grafted hydroxyethyl chitosan （DA（EO） ₅GE-g-HECTS）, a polymeric surfactant with hydrogenate phenanthrene ring as main lipophilic group, sugar chain of hydroxyethyl chitosan （HECTS） as main hydrophilic group, and polyoxyethylene chain as assist lipophilic-hydrophilic structure, was prepared through the grafting modification of DA（EO） ₅GE to water-soluble HECTS. The structure of the grafted product was characterized by Fourier transform infrared （FT-IR）, ¹H nuclear magnetic resonance ¹H NMR and UV-Vis spectrophotometry. The grafting degree （DG） of products were characterized using elemental analysis, and their surface-active activities and emulsifying capacity were investigated using surface tension method and emulsion stabilization time method, respectively. The result show that the DA （EO） ₅GE-g-HECTS with different DG can be prepared by using different raw material ratio. When the DG of DA（EO） ₅GE-g-HECTS increases from 12.98% to 31.73%, the critical micelle concentration （cmc） decreases from 0.378 g/L to 0.249 g/L. The emulsions are prepared by blending 50% （φ/%） liquid paraffin and 50% （φ/%） DA（EO） ₅GE-g-HECTS aqueous suspensions. The emulsifying capacity of DA（EO） ₅GE-g-HECTS increases at first and then decreases with the increasing DG. When the DA（EO）₅GE-g-HECTS4 （its DG is 28.33% and the mass concentration is 1.0 g/L） is utilized as emulsifier, the stability time of emulsion composed of liquid paraffin and water is 565 s. It is better than the TX-10 emulsifier which is 165 s at the same condition.

Key words: dehydroabietyl polyoxyethylene glycidyl ether, hydroxyethyl chitosan, grafting modification, surface-active activity