Synthesis And Characterization Of A Series Of Novel Rod-coil Block Copolymers

Rod-coil block copolymers attaract interest because of the expected and experimentally found richness of self-asembling morphologies. The recent literature reporting rod-coil block copolyers with well controlled microphase morphologies were briefly summarized in the first part of this dissertation. In this paper, we firstly optimized the synthesis of monomer 2,5-bis [(4-methoxyphenyl) oxycabony] (MPCS). Then three series of novel rod-coil block copolymers, PCL-b-PMPCS, PMPCS-b-PCL-b-PMPCS and s-(PCL-b-PMPCS)3, were successfully synthesized. Both the dynamic properties and liquid crystalline behavior of them were studied carefully. 1. After deeply and widely studies, we have optimized the monomer synthesis condition. 2. The PCL with one and two hydroxyl end groups were obtained from ε-caprolactone initiated by 1-butanol and ethylene glycol respectively. Then linear bromoisobutyryl PCL macroinitiator (PCL-Br and Br-PCL-Br) for ATRP was obtained by the modification of PCL by 2-bromoisobutyryl bromide. At last, the rod-coil di and triblock copolymers (PCL-b-PMPCS and PMPCS-b-PCL-b-PMPCS) were successfully synthesized via atom transfer radical polymerization in chlorobenzene solution using macro-initiator and CuBr/Sparteine complex as catalyst, the structure of which were confirmed by 1H NMR. The liquid crystalline behavior of them were studied using DSC and POM. 2. The tri-arm star initiator was obtained from the PCL initiated by trimethylolpropane. Then the star shaped rod-coil block copolymer S-(PCL-PMPCS)₃ was obtained via ATRP. Then we characterize them using GPC and 1^HNMR. Furthermore, the liquid crystalline behavior and phase transiation of S-(PCL-PMPCS)₃ was studied using DSC and POM.