月桂酸纤维素酯的均相法合成

Homogeneous synthesis of lauric acid cellulose esters

在纤维素LiCl/N,N-二甲基乙酰胺(DMAc)均相溶液体系中,以对甲苯磺酰氯(TosCl)为共反应剂,原位活化月桂酸,合成了月桂酸纤维素酯。采用红外光谱、核磁共振、热重等分析手段对产品进行了表征。考察了反应物配比、温度、时间等酯化条件对产品取代度的影响。结果表明:酯化产品的取代度与反应物纤维素葡萄糖苷、月桂酸和对甲苯磺酰氯的配比、反应温度及反应时间有关。在最佳酯化条件下,所得产品的取代度(DS)为2.58。热重分析结果表明,酯化反应削弱了纤维素分子间及分子内的作用力,赋予了月桂酸纤维素酯较好的热加工性。月桂酸纤维素酯在有机溶剂中的溶解度随取代度的增加而提高。

Lauric acid cellulose esters were synthesized in cellulose/LiCl/N,N-dimethylacetamide（DMAc）homogenous solution using p-toluenesulfonyl chloride for the in-situ activation of lauric acid.Structure and properties of the obtained lauric acid cellulose esters were characterized by means of IR,1H NMR,TG,etc.The esterification conditions were investigated and the results showed that the degree of substitution（DS） was influenced by mole ratios of cellulose repeat units/lauric acid/p-toluenesulfonyl chloride,reaction temperature and reaction time.Under the optimized reaction conditions,the highest DS was 2.58.TG analysis revealed that the inter-and intra-molecular interaction of cellulose was weakened by the esterification,and hence the cellulose lauric acid esters were endowed with preferable thermal processing characteristic.The products are soluble in various organic solvents,depending on the DS.