Organocatalytic sequential ring-opening polymerization of cyclic ester/epoxide and N-sulfonyl aziridine: metal-free and easy access to block copolymers
Organocatalytic sequential ring-opening polymerization of cyclic ester/epoxide and N-sulfonyl aziridine: metal-free and easy access to block copolymers
复制标题
环酯/环氧化物和N-磺酰基氮丙啶的有机催化顺序开环聚合：不含金属且易于获得嵌段共聚物
DOI：
10.1039/d1py00890k
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发表时间：
2021-08-26
影响因子：
4.6
通讯作者：
Zhang, Zhen
中科院分区：
文献类型：
--
作者：
Huang, Huishan;Luo, Wenyi;Zhang, Zhen
我们报道了一种有机催化顺序开环聚合（ROP）方法，用于简便合成基于聚磺酰胺的共聚物。首先使用醇和甲氧基聚乙二醇作为（大分子）引发剂，在对甲苯磺酰异氰酸酯的辅助下对N - 磺酰基氮丙啶进行ROP，以制备可控性良好的聚合物。对甲苯磺酰异氰酸酯有效地将羟基物种转化为对甲苯磺酰氨基甲酸酯阴离子，这是N - 磺酰基氮丙啶ROP的引发位点。然后在磷腈碱t - Bu - P - 2或t - Bu - P - 4存在下本体进行ε - 己内酯或环氧丙烷的ROP，接着用对甲苯磺酰异氰酸酯进行端基转化，随后进行N - 磺酰基氮丙啶的ROP。合成的聚（ε - 己内酯） - 嵌段 - 聚磺酰胺和聚（环氧丙烷） - 嵌段 - 聚磺酰胺共聚物在摩尔质量和分散度方面显示出显著的可控性。由二醇和三醇引发剂成功制备了定义明确的三嵌段和三臂星形共聚物。
We report an organocatalytic sequential ring-opening polymerization (ROP) approach for the facile synthesis of polysulfonamide-based copolymers. Alcohols and methoxylpolyethylene glycols were initially employed as (macro)initiators for the ROP of N-sulfonyl aziridines to produce well-controlled polymers with the assistance of tosyl isocyanate. Tosyl isocyanate efficiently transformed the hydroxyl species into the tosylcarbamate anion, the initiating site for the ROP of N-sulfonyl aziridines. ROP of e-caprolactone or propylene oxide was then performed in bulk in the presence of the phosphazene base t-Bu-P2 or t-Bu-P4, followed by end-group transformation with tosyl isocyanate and the subsequent ROP of N-sulfonyl aziridines. The synthesized poly(e-caprolactone)-block-polysulfonamide and poly(propylene oxide)-block-polysulfonamide copolymers showed a remarkable control of molar masses and dispersities. Well-defined triblock and 3-arm star-shaped copolymers were successfully prepared from diol and triol initiators.