Synthesis Of Acetal Derivatives As Gelators

Under the condition of high cut disperse emulsification and C12 alkyl benzenesulfonic acid as catalyst, 1,3:2,4-dibenzylidene sorbitol (DBS) and 1,3:2,4-di-(p-methylbenzylidene) sorbitol (MDBS) were prepared from sorbitol with benzaldehyde and p-methylbenzaldehyde in cyclohexane/methanol system as solvent respectively.Benzaldehyde and p-methylbenzaldehyde was preferably used in an amount of 2.1 moles per mole of sorbitol. High yield could be gained by the lower speed of removing the mixture of methanol and resultant water and the addition of cyclohexane/methanol several times. More fine properties of products could be gained by adding sodium hydroxide as neutralization process, and using water and methanol in sequence to purify product.For the process of preparing MDBS, the batchwise feeding of 4-methylbenzaldehyde was helpful to converting the gel state to wet powder as the product's higher gelation ability.The process in this paper were available for industrialization. The yield of DBS product in the laboratory experiments was up to 93.8%, with the purity of 99% and the melt point of 222.0~222.7℃. The yield of MDBS product was 96.8%, with the purity of 99.5% and the melt point of 248.1~249.4℃. Both of them had fine surface appearance, and their properties were the same as first-class products in the world.A series of poly alcohol acetal derivatives as gelators were synthesized by condensation between aromatic aldehyde and ploy alcohol such as sorbitol,mannitol,xylitol, and the products'gelation ability were tested with various kinds of organic solvent. The relation between the gelation ability of products and the structures of different kinds of poly alcohol were studied, also the effects of aromatic aldehydes with different substituent position should be focused on.