ATRC法合成蝌蚪型及杠铃型环状聚合物

具有特定臂数的星型聚合物通过分子内链末端偶联反应可以制备出不同形状的环状聚合物。文中以三臂含溴代异丁酸酯为引发剂(Tri-Br),通过先核后臂的方法制备出三臂星型聚苯乙烯(PSt_3)。然后将合成的三臂星型聚苯乙烯(PSt_3)在极稀浓度条件下,利用原子转移自由基偶合(ATRC)技术合成一端为大分子环状,一端为线型聚合物链的蝌蚪型环状聚合物(Tadpole-PSt_3)。最后在高浓度条件下,通过ATRC技术,使三臂聚苯乙烯未参与分子内偶联的线型链段进行分子间偶合制备出杠铃型环状聚合物(Barbell-PSt_3)。使用核磁共振、凝胶渗透色谱对聚合物结构进行了表征。结果表明,成功合成了纯度较高的蝌蚪型环状聚合物,同时进一步合成了中间为聚合物链段两端为大环的杠铃型环状聚合物。

Synthesis of Tadpole and Barbell Cyclic Polymers Via ATRC

Cyclic polymers with different shapes can be prepared by intramolecular terminal-terminal coupling of the star polymers with a defined number of arms.In this paper,tri-arm containing bromo isobutyrate as initiator (Tri-Br),then the tri-arrn star polystyrene was prepared by atom transfer radical polymerization (ATRP).The Tadpole-PSt3 was synthesized via intramolecular atom transfer radical coupling (ATRC) reaction of tri-arm star polystyrene solution under high dilute condition.Finally,the Barbell-PSt3 was also prepared via ATRC reaction of Tadpole-PSt3 under high concentration condition.The structures of Tadpole-PSt3 and Barbell-PSt3 were characterized by 1H-NMR and gel permeation chromatography (GPC).The results show that high-purity cyclic polymers (Tadpole-PSt3,Barbell-PSt3) are successfully synthesized.