Chen Weiqing, Wu Zhaoji, Wang Zhengge, Chen Changjiu, Zhang Zhigang
College of Chemical Engineering, Hebei Normal University of Science and Technology Qinhuangdao 066600 China
RSC Adv. 2022 Apr 25;12(20):12363-12370. doi: 10.1039/d2ra01610a. eCollection 2022 Apr 22.
A sulfonated porous polymer monolith (PPM-SOH) has been prepared the polymerisation of styrene (St) and divinyl benzene (DVB) with organic microspheres as pore-forming agents, followed by sulfonation with concentrated sulfuric acid. It was characterized by acid-base titration in order to determine its acid density, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, mercury intrusion porosimetry (MIP) and thermogravimetric analysis (TG). The PPM-SOH showed an acid density of 1.89 mmol g and pore cavities with an average diameter of 870 nm. The catalytic activity of PPM-SOH in practical biodiesel synthesis from waste fatty acids was investigated and the main reaction parameters were optimized through orthogonal experiment. The best reaction conditions obtained for the optimization of methanol to oil ratio, catalyst concentration, reaction temperature and reaction time were 1 : 1, 20%, 80 °C and 8 h, respectively. PPM-SOH showed excellent catalytic activity. In biodiesel synthesis, the esterification rate of PPM-SOH is 96.9%, which is much higher than that of commercial poly(sodium--styrenesulfonate) (esterification rate 29.0%). The PPM-SOH can be reused several times without significant loss of catalytic activity; the esterification rate was still 90.8% after 6 cycles. The pore size of this porous polymer monolith can be controlled. The dimension and shape of this porous polymer monolith were also adjustable by choosing a suitable polymerisation container.
通过以有机微球为致孔剂使苯乙烯（St）和二乙烯基苯（DVB）聚合，随后用浓硫酸磺化，制备了一种磺化多孔聚合物整体柱（PPM-SOH）。通过酸碱滴定对其进行表征以确定其酸密度，采用扫描电子显微镜（SEM）、透射电子显微镜（TEM）、傅里叶变换红外（FT-IR）光谱、压汞法（MIP）和热重分析（TG）。PPM-SOH的酸密度为1.89 mmol/g，平均直径为870 nm的孔腔。研究了PPM-SOH在由废脂肪酸实际合成生物柴油中的催化活性，并通过正交实验优化了主要反应参数。优化甲醇与油的比例、催化剂浓度、反应温度和反应时间得到的最佳反应条件分别为1∶1、20%、80℃和8 h。PPM-SOH表现出优异的催化活性。在生物柴油合成中，PPM-SOH的酯化率为96.9%，远高于市售聚（苯乙烯磺酸钠）（酯化率29.0%）。PPM-SOH可以重复使用多次而催化活性无明显损失；6次循环后酯化率仍为90.8%。这种多孔聚合物整体柱的孔径可以控制。通过选择合适的聚合容器，这种多孔聚合物整体柱的尺寸和形状也可以调节。
