文摘
Alkyl glucosides surfactants are synthesized by a cascade process that involves the methanolysis of cellulose into methyl glucosides followed by the transacetalization with n-octanol. The first step was performed using methanol as solvent and acid catalysts (such as, inorganic acids, heteropolyacids, ionexchange resins, or modified carbon materials). Subsequently, long-chain alkyl glucosides are obtained in the second step by transacetalization, which involves the reaction of methyl glucosides with a fatty alcohol using the same acid catalyst. The overall process was performed under mild conditions. Amorphous sulfonated carbon catalyst achieved the best results for the complete conversion of cellulose in methanol at 200 °C with methyl α,β-glucopyranosides yields higher than 80 %. Moreover, this material containing −SO3H groups is ideal to perform the second step to obtain octyl and decyl glucosides in yields higher than 73 % at 120 °C. In addition, the sulfonated carbon catalyst (C−SO3H) can be reused with only a slightly decrease of its activity after four consecutive cycles.