- Synthesis and properties of two surfactants containing polyoxypropylene block and short branched alkyl chain
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Short branched alkyl polyoxypropylene sulfates, sodium isohexyl polyoxypropylene sulfate (i-HPS) and sodium isooctyl polyoxypropylene sulfate (i-OPS) were synthetized via propoxylation, sulfation, and neutralization three-step reactions, and characterized by FT-IR and 1H NMR. Their Krafft points were measured and the results were all below freezing point. Their critical micelle concentrations (cmc) and minimum surface tension (γcmc) determined by equilibrium surface tension were 54.74 mmol L-1 and 32.12 mN m- 1 for i-HPS, 15.57 mmol L-1 and 33.33 mN m-1 for i-OPS, respectively. The measurement of dynamic surface tension indicated that both the equilibrium values of surface tension and the time required for reaching the equilibrium decreased with the increasing concentration of surfactant solutions. The spreading ability on paraffin film researched through dynamic contact angle revealed that the droplet of i-HPS solution presented a minimum contact angle of 58.9°at a concentration of 150 mmol L-1, while the equilibrium contact angle of i-OPS droplet was 52.8°under the same condition. Their salt tolerance measurement showed that 1.0 wt% i-HPS solution and 1.0 wt% i-OPS solution could endure 183.1 g L-1, 143.9 g L-1 NaCl, 206.3 g L-1, 198.4 g L-1 MgCl2, and 229.7 g L- 1, 217.9 g L-1 CaCl2, respectively.
- Wang, Wanxu,Li, Jianbo,Yang, Xiaoyi,Li, Ping,Guo, Chaohua,Li, Quanhong
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- Synthesis and properties of a branched short-alkyl polyoxyethylene ether alcohol sulfate surfactant
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A branched alkyl polyoxyethylene ether alcohol sulfate, sodium isooctyl polyoxyethylene ether sulfate (i-OE3S), was synthesized and its physic-chemical properties were investigated systematically. The experiment on Krafft point gave a result that the Krafft temperature of i-OE3S was below 0 °C. The measurement of static surface tension showed that the critical micelle concentration (cmc) and surface tension at cmc (γcmc) of i-OE3S were 21.67 mmol·L- 1 and 27.4 mN·m- 1, respectively. From the results of dynamic surface tension (DST) measurements, we could obtain that the adsorption of i-OE3S at air/liquid interface is controlled by the mixed diffusion-kinetic mechanism. Spherical assemblies with a diameter in the range of 263 to 606 nm in water were observed by transmission electron microscopy (TEM). The spreading performance of i-OE3S aqueous solution on paraffin film was investigated by dynamic contact angle and the results demonstrated that i-OE3S possessed an excellent spreading ability.
- Wang, Wanxu,Li, Jianbo,Yang, Xiaoyi,Li, Ping,Guo, Chaohua,Li, Quanhong
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- Topical mosquito repellents VII: Alkyl triethylene glycol monoethers
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Normal and branched chain aliphatic monoethers of triethylene glycol are effective topical mosquito repellents. In terms of duration of protection, they are generally superior to the corresponding diethylene glycol analogs, and some are superior to diethyltoluamide. The n heptyl monoether of triethylene glycol affords double the protection time of diethyltoluamide under controlled laboratory conditions, and appears to be a useful new mosquito repellent.
- Johnson,DeGraw,Engstrom,Skinner,Brown,Skidmore,Maibach
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p. 693 - 695
(2007/10/05)
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