Macromolecules, Vol.36, No.22, 8330-8335, 2003
Simplified synthesis of amphiphilic siloxanes with methyl gluconyl glycinate functionalities via transacetalation
New carbohydrate-functional siloxanes (CHFS) have successfully been synthesized by acid-catalyzed transacetalation between unprotected methyl gluconyl glycinate (MGG) as a hydrophilic component and an acetal-functional siloxane in DMF/dioxane mixed solvents. MGG, which can be regarded as a hybrid material composed of a saccharide and an amino acid, was easily synthesized in good yield by amide bond formation between D-glucono-1,5-lactone and glycine methylester hydrochloride. It was demonstrated that both amide and ester groups remained inactive under the transacetalation conditions. A rake-type CHFS as well as an ABA-type CHFS was obtained without an insolubilization problem indicating that the use of this modified carbohydrate is very advantageous in terms of the structural versatility. The materials thus obtained were soluble in both nonpolar solvents such as chloroform and polar solvents such as DMF and DMSO. The hydrophilicity of MGG, glucose, and poly(ethylene oxide) was estimated by the solubility parameter values and compared with the water solubility data. A simple emulsification study of CHFS suggested that these new materials are worth being investigated deeply to find applications, especially personal care and healthcare applications.