Preparation Of Fe₃O₄ Supported ZnO Catalyst And Study On Catalytic Synthesis Of Rosin Polyol Ester

Rosin is a very important type of natural resources.It has the characteristics of moisture resistance,corrosion resistance,adhesiveness,etc.,and can be used in industries such as ink production,coatings,food and rubber production.However,due to the fragility,high acid value,and high softening point of rosin itself,its industrial use is greatly limited.Therefore,in order to solve the above problems,the modification of rosin has become one of the main problems in today's research.The most common modification of rosin is esterification,and the common esterification reaction products are rosin glycol ester,rosin glyceride,and rosin pentaerythritol ester.In order to overcome the problems of low catalytic activity,difficult recovery,and poor reusability of the catalysts used in traditional rosin polyol esters,a eutectic solvent and Fe3O4supported catalysts were designed and synthesized.The effect of the prepared catalyst on the esterification of rosin was investigated.The effect of the reaction is as follows:?1?The eutectic solvent was used as a catalyst to catalyze the synthesis of rosin glyceride.The optimal conditions for synthesizing rosin glyceride were:The best eutectic solvent for the reaction was ChCl-TsOH,the amount of catalyst was 0.3 g,the reaction time was 5 h and the reaction temperature was 230?.FT-IR was performed on the product,which proved that the target product was obtained.The eutectic solvent used has the characteristics of easy synthesis,low cost,non-toxicity,etc.,but its recyclability is poor,so it is not easy to conduct further research.?2?The structure of the synthesized Fe₃O₄@ZnO was characterized by XRD and XPS,and the morphology of Fe₃O₄@ZnO was characterized by TEM,which proved the successful synthesis of the catalyst.The synthesis of rosin glycol ester,rosin glyceride,and rosin pentaerythritol ester was catalyzed by Fe₃O₄@ZnO as a catalyst.The optimum conditions for the synthesis of rosin glycol ester were zinc acetate as the best zinc source and the load of zinc source was 0.45 g,catalyst dosage is 0.2 g,rosin 15 g,ethylene glycol 3.15 g,reaction temperature is 270?,reaction time is 5h;the optimal conditions for the synthesis of rosin glyceride are zinc sulfate as the optimal zinc source and the zinc source loading 0.45 g,catalyst dosage is 0.3 g,rosin 15 g,glycerin 3.5 g,reaction temperature is 240?,reaction time is 5 h;the optimal conditions for the synthesis of rosin pentaerythritol ester are zinc nitrate as the best zinc source,and the zinc source load is 0.25 g,the amount of catalyst used was 0.2 g,rosin 15 g,pentaerythritol 1.7 g,the reaction temperature was 250?,and the reaction time was 5 h.FT-IR was performed on the product,which proved that the target product was obtained.The Fe₃O₄@ZnO catalyst used has significantly improved catalytic activity compared to traditional homogeneous catalysts,but its recyclability is poor.Therefore,Fe3O4@ZnO was modified on this basis to continue further research.?3?The structure of the synthesized Fe3O4@SiO2-ZnO was characterized by XRD and XPS,and the morphology of Fe3O4@SiO2-ZnO was characterized by TEM,which proved the successful synthesis of the catalyst.The acidity and acidity distribution of Fe3O4@SiO2-ZnO were characterized by NH₃-TPD and Py-IR,which proved that the catalyst has B acid center and L acid center.The synthesis of rosin glycol ester,rosin glyceride,and rosin pentaerythritol ester was catalyzed by Fe3O4@SiO2-ZnO catalyst.The optimal conditions for the synthesis of rosin ethylene glycol ester were that zinc chloride was the zinc source,and the theoretical load of zinc source was 0.45g,reaction temperature is 270°C,reaction time is 5 h,rosin is 15.0 g,ethylene glycol is 3.2 g,and the amount of catalyst is 0.2 g;the optimal conditions for the synthesis of rosin glyceride are zinc acetate as the zinc source,and the theoretical load of the zinc source,the amount is 0.25 g,the reaction temperature is 240°C,the reaction time is 5 h,rosin is 15.0 g,glyceride is 3.2 g and the amount of catalyst is 0.2 g.The optimal conditions for the synthesis of rosin pentaerythritol ester are zinc nitrate as the zinc source,the theoretical load of zinc source is0.45 g,and the reaction temperature is 250?,reaction time was 5 h,rosin is 15.0 g,pentaerythritol is 1.7 g and the amount of catalyst was 0.2 g.FT-IR was performed on the product,which proved that the target product was obtained.Compared with Fe₃O₄@ZnO,the used Fe3O4@SiO2-ZnO catalyst has higher catalytic activity,and its recovery and useability are good.After repeated 5 times,the catalytic activity does not decrease significantly,so it shows that the synthesized Fe3O4@Si O2-ZnO catalyst good stability.