| Cyclic polystyrenes with two hydroxyl groups have been prepared by using a living coupling agent based on 1,3-bis(1-phenylethenyl)benzene (DDPE) followed by end-capping with ethylene oxide. The functionality of ;A hydrocarbon-soluble dilithium initiator has been chosen for the preparation of cyclic polybutadienes. Cyclic polybutadienes and cyclic analogs of linear SBS triblock copolymers with high 1,4-microstructure have been obtained using a DDPE/sec-BuLi/LiOBu initiating system followed by coupling with DDPE or dichlorodimethylsilane. In an attempt to obtain a more reactive initiator, 1,3-bis (1-(4-methoxyphenyl)ethenyl) benzene (DDMPE) has been prepared and used to make cyclic polybutadienes with two anisyl groups. A cyclic polybutadiene with two polystyrene branches has also been made using the living coupling agent method. |
