改性活性白土催化油酸合成二聚酸

Catalytic Synthesis of Dimer Acid from Oleic Acid over Modified Activated Clay

以油酸为原料,活性白土为催化剂合成二聚酸。利用HPLC方法和正交实验考察了适宜的工艺条件。实验结果表明,优化的工艺条件为:常压、反应温度240℃、反应时间6 h、活性白土用量为油酸的12%(w)、Li Cl用量为油酸的1.2%(w),在此条件下二聚酸的收率为34.6%。采用路易斯酸和有机化合物对活性白土进行无机和有机改性,并研究了路易斯酸的类型和有机插层对油酸常压聚合生成二聚酸的影响。实验结果表明,随路易斯酸性的增强,二聚酸的收率逐渐增加,适宜的路易斯酸为Al Cl3,用量为活性白土的3.3%(w),二聚酸收率可提高至55.9%。用十六烷基三甲基溴化铵改性活性白土时,适宜的用量为活性白土的0.6%(w),二聚酸收率为54.5%。

Dimer acid was prepared from oleic acid on activated clay catalyst. The appropriate preparation conditions were investigated by means of HPLC and orthogonal experiments. The results indi- cated that under the optimal conditions of normal pressure, reaction temperature 240 ℃, reaction time 6 h, activated clay dosage 12% （w） （based on the oleic acid） and cocatalyst LiCl dosage 1.2% （w） （based on the oleic acid）, the dimer acid yield was 34.6%. The activated clay was modified with Lewis acids or organic compounds. The effects of the Lewis acids and organic compounds on the yield of dimer acid were studied. The results showed that with the increase of the Lewis acid＇s acidity, the yield of the dimer acid increased and the suitable Lewis acid was AlCl3. When the AlCl3 dosage was 3.3% （w） of the activated clay dosage, the dimer acid yield was 55.9%. The catalytic performance of the activated clay after modification with cetyltrimethyl ammonium bromide （CTAB） was enhanced, and when the CTBA dosage was 0. 6% （w） of the activated clay dosage, the dimer acid yield was 54.5%.