Grignard Metathesis Chain-Growth Polymerization and Characterization of Rod-Rod Diblock Copolymers of Polyparaphenylene-b-poly(3-hexylthiophene)

In this thesis, we studied the synthesis of rod-rod diblock copolymers via Grignard Metathesis chain-growth polymerization, and the self-assembling behavior lead to phase separation. The rod-rod diblock copolymer which was composed by poly(2,5-dihexyloxy-p-phenylene (PPP) and poly(3-hexylthiophene) (P3HT), and we synthesized five different composition which all of the PPP molecular weight is about 4000, the polydispersity index (PDI) of PPP is lower than 1.2, and then polymerized to various molecular weight of PPP-b-P3HT. The fraction of PPP in the PPP-b-P3HT diblock copolymer is about 15%~70%. The synthesized PPP-b-P3HTs were characterized by using various techniques including gel permeation chromatography (GPC) to ensure molecular weight and PDI of diblock copolymer, 1H-Nuclear Magnetic Resonance (1H-NMR) to ensure each of the fractions of PPP and P3HT in diblock copolymer, UV-VIS and photoluminescence (PL) to analysis photo characterization and compare which of the difference, thermogravimetric analysis (TGA) to compare the difference between thermoresistivity of various composition of the diblock copolymers. Furthermore, the self-assembling behavior of block copolymer was investigated by TEM. We observed lamellae and fiber, which has different microphase structures for different compositions of the diblock copolymers. In the end, we used the small angle X-ray scattering technique to calculate the length of diblock copolymer, and the wide angle X-ray scattering technique to study the crystalline of PPP-b-P3HT nanostructure. We could observe that PPP-b-P3HT diblock copolymers which microphase structures within nanometer, and with difference between each of homopolymers. We could recognize the basic property and microscopic self-assembling behavior of PPP-b-P3HT by the techniques. We also synthesized poly(3-hexylthiophene)-b-poly(3-hexyloxythiophene) (P3HT-b-P3HOT) by Grignard Metathesis and characterized by using various techniques to compare the difference between PPP-b-P3HT in appendix.