利用偶合反應法合成聚對苯乙烯-聚2 乙烯之 硬桿-柔曲塊狀共聚高分子及其自組裝特性研究

Abstract

Recently, the self-assembling behavior of rod-coil block copolymers has been rapidly explored. In the thesis, an aldehyde-terminated poly(phenylene vinylene) (PPV) was synthesized by Siegrist polycondensation method, and the polymer had a number average molecular weight of 5000g/mol with narrow polydispersity. In addition, a monodispersed homopolymer living anion of poly(2-vinyl pyridine) (P2VP) was synthesized via anionic polymerization using sec-butyllithium as an initiator. Block copolymers of PPV-b-P2VP were synthesized by a nucleophilic addition reaction between P2VP living anion and aldehyde-terminated PPV. Five PPV-b-P2VP block copolymers with different PPV/P2VP molar ratio were successfully synthesized with high yield (>90%). The synthesized PPV-b-P2VPs were characterized by using various techniques including gel permeation chromatography (GPC), UV-VIS, photoluminescence (PL), TGA (thermogravimetric analysis) and differential scanning calorimetry (DSC). Furthermore, the self-assembling behavior of block copolymers was investigated by using TEM. Different microphase structures, e.g. lamellae, cylinders, and spheres were observed for different compositions of the copolymers. In the end, we used the wide angle X-ray scattering technique to study the crystalline structure of PPV in the PPV-P2VP nanostructure. It was found that the crystallinity of PPV decreases with increasing P2VP molecular weight.