磺酸化聚苯乙烯微球催化合成N-(乙氧基亚甲基)苯胺

Synthesis of Ethyl N-phenylformimidate Catalyzed by Surface-sulfonated Polystyrene Microspheres

摘要:

首先通过无皂乳液聚合制得聚苯乙烯（PS）种子乳液，再加入苯乙烯磺酸钠继续进行无皂乳液聚合，得到核壳结构的苯乙烯-苯乙烯磺酸钠共聚物微球(PS-NaSS@PS)，然后酸化，得到表面磺酸化的微球(PS-HSS@PS)。以PS-HSS@PS作为可回收的催化剂合成N-(乙氧基亚甲基)苯胺，并与对甲苯磺酸、商品化的强酸阳离子交换树脂的催化性能进行对比。结果表明，PS-HSS@PS的磺酸基含量和加入量对催化性能影响较大，磺酸基含量较高的PS-HSS@PS催化性能优异，收率可以达到97%，其活性优于强酸阳离子交换树脂(收率89%)，与对甲苯磺酸相当(收率98%)，且循环使用性能良好，循环使用5次后，收率仍可达到97%左右。

Abstract:

The polystyrene (PS) seed emulsion was firstly prepared by soap-free emulsion polymerization. Styrene-styrene sulfonate copolymer microspheres (PS-NaSS@PS) with core-shell structure was then synthesized through polymerization of sodium p-styrenesulfonate in the PS seed emulsion. Followed by acidizing, surface sulfonated microspheres (PS-HSS@PS) was obtained. Ethyl N-phenylformimidate was synthesized with PS-HSS@PS as a recoverable catalyst. Its catalytic performance was compared with p-toluene sulfonic acid and commercially available strong acidic cation-exchange resin. The results showed that the sulfonic acid group content and the addition amount of PS-HSS@PS had a great influence on the catalytic performance. The catalytic activity of PS-HSS@ PS with high sulfonic acid content was excellent and the yield was up to 97%. The activity of PS-HSS@ PS was higher than that of srong acidic cation-exchange resin (89% of the yield), and comparable to p-toluene sulfonic acid (98% of the yield). Furthermore, PS-HSS@PS had excellent recyclability and the yield could reach 97% after 5 cycles.