中文摘要：

以杂多酸为催化剂、不同链长的二元酸为原料，合成了系列长碳链二元酸二元酯，考察了影响合成反应的因素及碳链长度对合成酯物化性能的影响．结果表明，在回流温度160℃、醇／酸摩尔比3：1、催化剂用量为总质量1％、反应时间120min、带水剂用量为总质量10％的条件下，酯化率达98％以上．合成的酯具有良好的物化性能，其倾点最低为-74℃，闪点最高为258℃，粘度指数最大为187，优于现有商业化酯类润滑油基础油，达到现有航空润滑油基础油的标准．随着碳链增长，合成酯粘度增大，增加醇碳链长度对粘度的影响大于增加酸碳链长度的影响．

英文摘要：

A series of long-chain diester were synthesized by using dicarboxylic acid as raw material and polyoxometalates as catalyst, and the influential factors on the synthesis reaction were studied. It is found that under the conditions of 160 ℃, molar ratio of alcohol to acid 3：1, 1% catalyst content and 10% dehydrator content, the yield of esterification can reach over 98%. The synthesized diesters exhibit excellent physicochemical properties. Their freezing point can reach -74 ℃, flash point 258 ℃, and viscosity index 187, which is much better than commercial lubricant base oil and close to the standard of aviation lubricant base oil. The effect of chain length on the physicochemical properties of the esters was studied. It is found that with the increase of the chain length, their viscosity is increased significantly. And the chain length on the alcohol part plays a key role in the final viscosity of the diesters.