Study On Synthesis And Application Of Sorbitol Acetal Derovatives As Gelator

In this work, allyl sorbitol acetals and sorbitol dialdehyde carbamates weresynthesized. The gel properties of the compounds were tested. Then, LIB gelelectrolyte was prepared and studied.In this work,1-allyl sorbitol was synthesized from D-glucose.9kinds of allylsorbitol acetals were synthesized from1-allyl sorbitol and benzaldehyde or substitutedbenzaldehyde though acetalization reaction. Then gel properties of the compoundswere tested and compared with sorbitol acetals. The optimum reaction conditions forpreparation of1-allyl sorbitol acetal were: alcohol and water (v_alcohol: v_water=6:1) asmixed solvent, nitrogen protection, reaction temperature60°C, reaction time24h,batchwise feeding, mol ratio D-glucose: Sn: allyl bromide=1:2:3.3, the reaction wasover when D-glucose disappeared completely. The yield of1-allyl sorbitol was up to70%. Then the crude product was used without further purification. Allyl sorbitolacetals were synthesized at optimum reaction conditions: mol ratio1-allyl sorbitol:laldehyde=1:2.2; room temperature;6-8h; the yield of the products was from5.2%to19.7%. Found by gel properties tests, allyl sorbitol acetals had good gelationabilities in aromatic and alcohol solvents. In aromatic solvents and long-chain alkanesolvents, allyl sorbitol acetals had better gelation abilities than sorbitol acetals.In this work, sorbitol dialdehyde carbamates were synthesised from1,3:2,4-bis （methyl-benzyl）-D-sorbitol （MDBS） and aliphatic isocyanate. Then gel propertiesof the compounds were tested. The results indicated that: the main driving force ofgelation of sorbitol acetal is hydrogen bonds of intermolecular between the6-OH andthe acetal oxygen of another molecule. When6-OH was changed into carbamatestructure, the abilities of gelation degraded; the minimum gel concentration wasreduced with the increase of the number of carbon atoms in the straight chain alcohols.And the result proved solvent molecules was involved in the formation of the gel.Allyl sorbitol acetals had good abilities of gelation in mixed solvent used byelectrolyte. Sorbitol acetal carbamate derivatives had poor abilities of gelation. Thenthe gelation ability of the gelators became poor when LiTFSI salt was added. Themeasurement of cyclic voltammetry and SEM of aluminum foil in the liquid electrolyte and gel electrolyte indicated that gel electrolyte effectively reduced thecorrosion of aluminum foil.