负载型杂多酸催化合成烷基二苯胺

研究了以α-C14烯烃(C1=4)、二苯胺为原料,S iO2负载磷钨酸为催化剂,经烷基化反应合成抗氧剂烷基二苯胺的新工艺。探讨了磷钨酸负载量、催化剂用量、反应物配比、反应温度、反应时间等对烷基化反应的影响,获得了适宜的工艺条件:磷钨酸负载量(质量分数)40%,催化剂用量(占总反应物的质量分数)1.0%,反应温度200℃,n(二苯胺)∶n(C14=)=1∶1.1,反应时间7h。在此条件下,二苯胺的转化率为98.2%。所得产物经检测为目的产品烷基二苯胺,产品质量已达到国外同类产品的标准。催化剂经35次重复使用的实验结果表明,催化剂的稳定性良好。催化剂活性降低的主要原因是反应物和生成物覆盖了催化剂的表面。同时提出了溶剂萃取再生催化剂的方法。

Synthesis of Alkyldiphenylamine on Supported Phosphotungstic Acid Catalyst

A novel technology for preparation of alkyldiphenylamine(ADPA)from α-olefin(C~=_(14))and diphenylamine with phosphotungstic acid supported on silica as catalyst was investigated.ADPA was high quality antioxidant for superior lubricants.By single factor experiment,effects of mass fraction of phosphotungstic acid,catalyst dosage,mole ratio of reactants,reaction temperature and reaction time on alkylation was studied.Optimal reaction conditions were as follows:mass fraction of phosphotungstic acid 40%,mass fraction of catalyst(1.0%) of total reactants,reaction temperature 200℃,(n(diphenylamine)) ∶n(C~=_(14))=1 ∶1.1 and reaction time 7h.Under above conditions,diphenylamine conversion could reach 98.2%.The product was analyzed by means of HPLC-MS and IR.After being reused 35 times,the catalyst still kept steady activity for alkylation.The fresh catalyst surface covered gradually by reactants and products led to structural change of the catalyst and consequently it became less active.Solvent extraction for regeneration of catalyst was proposed.