磺酸化聚苯乙烯微球催化合成N-(乙氧基亚甲基)苯胺

Catalytic Synthesis of Ethyl N-Phenylformimidate by Surfacesulfonated Polystyrene Microspheres

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-Na SS@PS),然后酸化,得到表面磺酸化的苯乙烯-苯乙烯磺酸微球(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,产物收率可达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,收率仍可达97%左右。

Polystyrene（ PS） seed emulsion was first prepared by soap-free emulsion polymerization.Then,seeded emulsion polymerization of sodium p-styrenesulfonate and styrene was carried out to give styrene-styrene sulfonate copolymer microspheres（ PS-Na SS @ PS） with core-shell structure. Finally,surface-sulfonated microspheres（ PS-HSS@ PS） were obtained by treatment of PS-Na SS@ PS with HCl aqueous solution. PS-HSS @ PS as a recoverable catalyst was used to synthesize ethyl Nphenylformimidate,and its catalytic performance compared with that of p-toluene sulfonic acid and commercially available strong acidic cation-exchange resin. The results showed that the content of sulfonic group and the addition amount of PS-HSS @ PS had a great influence on the catalytic performance. The PS-HSS @ PS with higher content of sulfonic group exhibited a higher catalytic activity. The yield of ethyl N-phenylformimidate on PS-HSS@ PS was up to 97%. The activity of PSHSS@ PS was higher than that of strong acidic cation-exchange resin（ 89%）,and comparable to that of p-toluene sulfonic acid（ 98%）. Furthermore,PS-HSS@ PS had an excellent recyclability,and the yield of ethyl N-phenylformimidate could still reach about 97% even after recycling for five times.