Synthesis And Properties Of Novel Trisiloxane Surfactants

Surfactants are provided with extensive applications in science research and industry and agriculture fields due to their highly influencing interface properties. It is always leading direction in the development of surfactants to seek high efficient, efficiency, green and novel surfactants. Synthesis of high efficient, efficiency, biodegradable and novel surfactants in according to surfactant molecular structure possess significant theoretic and practice significance.A series of glucosamide-based trisiloxane surfactants which have gathered the superior interface tension of trisiloxanes, the lower critical micelle concentration of Gemini surfactants and the better biological degradability of carbohydrate-based surfactants were synthesized in term of the theory of the relationship of surfactant structure and property in this dissertation. The surface tension and critical micelle concentration of these surfactants were determined. The spread ability and hydrolyzation were discussed.Chapter one. The research background and progress about trisiloxane surfactants, carbohydrate-based Gemini surfactants and carbohydrate-based silicone surfactants have been reviewed, including the synthesis technique, structure characteristic, interface property, phase behavior and microstructure and so on. The thought of this topic was brought forward.Chapter two. Two glucosamide-based trisiloxane surfactants were synthesized and their properties were determined. Their constructions were confirmed by nuclear magnetic resonance spectrometry (1H and 13C NMR) and elemental analysis. The interface properties of these glucosamide-based trisiloxane surfactants were determined by the Wilhelmy plate method using a Kriiss tensionmeter, model K12 and they can significantly reduce the surface tension of water to approximate 21 mN/m at critical aggregation concentration (CAC), 5~6x10-4. The spread abilities were evaluated by the contact angle in quartz using a Kruss tensionmeter, model K12 and the minimum, 15 was obtained in CAC. The hydrolyzations were studied by measuring surface tension change with time and that ofthese trisiloxane surfactants were very serious.Chapter three. Three glucosamide-based trisiloxane surfactants of substitution in the oxyethylene units were synthesized and their properties were determined. Their constructions were confirmed by nuclear magnetic resonance spectrometry (1H and 13C NMR) and elemental analysis. The interface properties of these glucosamide-based trisiloxane surfactants were determined by the Wilhelmy plate method using a Krttss tensionmeter, model K12 and they can significantly reduce the surface tension of water to approximate 21 mN/m at critical aggregation concentration (CAC), 2.46x10-4, 1.42x10-4, 5.99x10-5, respectively. The CAC values decreased with the oxyethylene units increasing. The spread abilities were evaluated by the contact angle in quartz using a Kruss tensionmeter, model K12 and the minimum, 4~17 was obtained in CAC. The hydrolyzation was studied by measuring surface tension change with time and that of these trisiloxane surfactants were very serious. The hydrolyzation decreased with the oxyethylene units increasing.Chapter four. Two glucosamide-based trisiloxane Gemini surfactants which were connected with the short carbon chain dialcohol diglycidyl ether spacer were synthesized and their properties were determined. These compounds were structurally characterized by their 1H and 13C NMR spectra and elemental analysis. The interface properties of these glucosamide-based trisiloxane Gemini surfactants were determined by the Wilhelmy plate method using a Kriiss tensionmeter, model K12. They can significantly reduce the surface tension of water to approximate 22-23 mN/m at critical aggregation concentration (CAC), 3x10-5. The CAC values increased with the carbon chain and were about 1~2 orders of magnitude lower than that of the corresponding monomer. The Gemini compounds showed two CAC values in its surface tension curve. The spread abilities were evaluated by the contact angle in...