In the last years diblock copolymers have gained a large interest in different flields of material science due to their unique self-assembling properties. „Rod-coil" diblock copolymers with one conjugated block and one non-conjugated block have been successfull synthesized. They show promising self-assembling properties. However, such „rod-coil" diblock copolymers often show disadvantageous electronic properties due tot he presence oft he isolating coil blocks. Therefore, the synthesis of „rod-rod" diblock copolymers was developed.
In chapter 2, the synthesis of fully conjugated fluorene-/thiophene- diblock copolymers is described. The first block is a monobrominated poly(3-alkylthiophene) generated via Grignard metathesis reaction, the second block is a nonpolar polyfluorene. In a polycondensation reaction of the fluorene monomer the polythiophene is added as a macromolecular endcapper to give the corresponding polyfluorene/polythiophene diblock copolymer. A bromo- functionalized alkyl chain of the polythiophene can be converted into a polar phosphonic ester function. The novel diblock copolymers show a solvent dependent aggregation behaviour, e.g. the ability to form vesicles.
In chapter 3, the synthesis of a conjugated donor/acceptor diblock copolymer is described. One block is again a monobrominated poly(3-alkylthiophene), the second block is an alternating fluorene/dithienyl-benzothiadiazole block. The monomer is polycondensed in a Stille-type reaction and P3AT is added as macromolecular endcapper to give the diblock copolymer. If the P3AT contains monobromo-functionalized alkylsidechains, they can be converted into hosphonic esters, phosphonic acids or cationic trimethylammonium functionalized sidechains. All polymers show promising self-assembly properties including solvent-selective aggregation behaviour.
In chapter 4, the synthesis of the first isotactic polyfluorene with two different alkyl chains is described. For this, a new synthetic route has been developed. Here, the key step is a enantiomeric separation on the monomer level via chiral HPLC. The chiral AB-type monomers can be polycondensed in a Suzuki-type cross coupling reaction to obtain isotactic polyfluorene. For comparison the atactic counterpart was also generated. Both polymers differ in their packing behaviour as shown in 2D-WAXS experiments and in their thermal behaviour.