球形聚萘并噁嗪树脂酸催化酯化反应

Spherical Polynaphthoxazine Resin Acid Catalyzed Esterification Reaction

研究了球形聚萘并噁嗪树脂酸催化剂的制备方法,考察了其对酯化反应的催化活性。萘并噁嗪预聚体在甲基硅油中反相悬浮固化得到球形聚萘并噁嗪树脂,再经磺化反应制得聚萘并噁嗪树脂酸,用扫描电子显微镜及其搭载的能谱仪(EDS)考察了催化剂的外貌特征和表面主要元素分布,用Tg分析了催化剂的热稳定性,通过催化冰醋酸与乙醇酯化反应评价了催化剂的活性。结果表明,球形聚萘并噁嗪树脂在300℃以下不发生热失重,45℃磺化得到的催化剂活性最高,树脂负载磺酸基团为4.29mmol/g。在反应时间2h,催化剂用量为冰醋酸质量分数的3%和n(醇)∶n(酸)=2∶1时,冰醋酸的转化率为77%。

Spherical polynaphthoxazine resin acid catalyst was prepared and applied to esterification reaction of glacial acetic acid and ethanol. Naphthoxazine precursor was converted into spherical polynaphthoxazine resin in methylsilicone oil by reversed-phase suspension polymerization, then polynaphthoxazine resin acid was generated from the reaction of sulfonation. Thermal stability and surface composition of the catalyst were measured by NETZSCH TG 209 and JSM-6390/LV SEM, respectively. Catalytic activity of the resin acid was evaluated through the esterification reaction of glacial acetic acid and ethanol . The results show that the pyrogenation of spherical polynaphthoxazine resin obtained by reversed-phase suspension polymerization will not take place at 300 ℃. Catalytic activity of the catalyst obtained from sulfonating spherical polynaphthoxazine resin at 45 ℃ is the highest, and there is 4. 29 mmol/g of sulfonic groups on the surface of resin. The conversion rate of glacial acetic acid was 77% with the catalyst obtained from sulfonation reaction at 45 ℃ when the reaction time was 2 h, catalyst dosage was 3% （on glacial acetic acid mass） and mole ratio of ethanol to acetic acid was 2： 1.