Conversion of rosin to its pentaerythritol ester provides a means of improving its water resistance, alkali resistance, and oxidation resistance, thereby increasing its stability. Rosin pentaerythritol ester is much more amenable to industrial applications than the parent compound. To overcome the difficulty of catalyst recovery and its associated high cost during the synthesis of rosin pentaerythritol ester, Fe3O4-supported ZnO catalysts, such as Fe3O4@ZnO and Fe3O4@SiO2–ZnO, have been designed and synthesized. The structures, morphologies, and compositions of the materials have been characterized by TEM, XRD, and XPS. The results of esterification reactions demonstrate that Fe3O4@SiO2–ZnO has excellent catalytic performance and stability. The degree of esterification in the production of rosin pentaerythritol ester reached 87.9%, far exceeding the yields attained with other catalysts. Moreover, the catalyst could be reused five times without incurring a loss of activity. The effects of zinc source, zinc loading, and reaction conditions on the esterification have been investigated in detail. This study provides a class of heterogeneous catalysts with excellent properties for the synthesis of rosin pentaerythritol ester. In our paper, the optimum process conditions for obtaining rosin pentaerythritol ester have been identified as zinc nitrate as the zinc source, a theoretical loading of zinc source of 0.45 g, a reaction temperature of 250 °C, a reaction time of 5 h, and a catalyst loading of 0.2 g, when starting from rosin (15 g) and pentaerythritol (1.7 g). The conversion rate was 87.9%, and the acid value was 25.0 mg KOH g−1. This research provides an improved protocol for the rosin esterification reaction.

中文翻译：

---

在 Fe3O4 负载的 ZnO 催化剂上制备松香季戊四醇酯

松香转化为其季戊四醇酯提供了一种提高其耐水性、耐碱性和抗氧化性的手段，从而增加了其稳定性。松香季戊四醇酯比母体化合物更适合工业应用。为了克服松香季戊四醇酯合成过程中催化剂回收困难及其相关的高成本，设计并合成了 Fe3O4 负载的 ZnO 催化剂，如 Fe3O4@ZnO 和 Fe3O4@SiO2–ZnO。材料的结构、形貌和成分已通过 TEM、XRD 和 XPS 表征。酯化反应结果表明 Fe3O4@SiO2-ZnO 具有优异的催化性能和稳定性。松香季戊四醇酯生产中酯化度达到87.9%，远远超过其他催化剂的产率。此外，催化剂可以重复使用五次而不会导致活性损失。详细研究了锌源、锌负载量和反应条件对酯化反应的影响。本研究为松香季戊四醇酯的合成提供了一类性能优异的多相催化剂。在我们的论文中，已确定获得松香季戊四醇酯的最佳工艺条件为以硝酸锌为锌源，锌源理论负载量为0.45 g，反应温度为250 °C，反应时间为5 h，当从松香 (15 g) 和季戊四醇 (1.7 g) 开始时，催化剂负载量为 0.2 g。转化率为87.9%，酸值为25.0 mg KOH g-1。