脱氢枞氧基聚氧乙烯缩水甘油醚接枝羟乙基壳聚糖制备及其表面活性

Preparation and surface-active properties of dehydroabietyl polyoxyethylene glycidyl ether grafted hydroxyethyl chitosan

脱氢枞醇聚氧乙烯(5)醚(DA(EO)_(5)H)在BF_(3)·乙醚催化下与环氧氯丙烷缩合后,再在NaOH存在下使生成的缩合产物进行分子内脱氯化氢,得到脱氢枞氧基聚氧乙烯(5)缩水甘油醚(DA(EO)_(5)GE);然后通过DA(EO)_(5)GE与水溶性羟乙基壳聚糖(HECTS)间的亲核加成反应,得到以氢化菲环为主要亲油基、HECTS为主要亲水基和聚氧乙烯链为辅助亲水亲油结构的高分子表面活性剂DA(EO)_(5)GE接枝HECTS(DA(EO)_(5)GE-g-HECTS)。用FT-IR、^(1)H NMR和UV-Vis表征了接枝产物结构,元素分析法测定了其接枝度(DG),表面张力法和乳液稳定时间法分别研究了产物的表面活性和乳化能力。结果表明:利用不同原料比,可以制备得到具有不同接枝度的DA(EO)_(5)GE-g-HECTS。当DA(EO)_(5)GE-g-HECTS的DG从12.98%增加至31.73%时,其临界胶束浓度(cmc)从0.378 g/L降至0.249 g/L,对液体石蜡-水乳液的乳化能力呈现先增强后减弱的趋势;以1.0 g/L的DA(EO)_(5)GE-g-HECTS4(DG为28.33%)水溶液与等体积液体石蜡形成的乳液,其稳定时间为565 s,优于TX-10为稳定剂时的165 s。

Dehy droabietol polyoxyethylene(5)ether(DA(EO)_(5)H)was condensated with epichlorohydrin in the presence of boron fluoride diethyl etherate firstly.Then,dehydroabietyl polyoxyethylene glycidyl ether(DA(EO)_(5)GE) was obtained through dehydrochlorination of the condensation product in the presence of NaOH.Finally,DA(EO)_(5)GE grafted hydroxyethyl chitosan(DA(EO)_(5)GE-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)_(5)GE to water-soluble HECTS.The structure of the grafted product was characterized by Fourier transform infrared(FT-IR),1H nuclear magnetic resonance ^(1)H 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)_(5)GE-g-HECTS with different DG can be prepared by using different raw material ratio.When the DG of DA(EO)_(5)GE-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)_(5)GE-g-HECTS aqueous suspensions.The emulsifying capacity of DA(EO)_(5)GE-g-HECTS increases at first and then decreases with the increasing DG.When the DA(EO)_(5)GE-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.