Synthesis and application of condensation polymers containing triarylamine groups

Abstract

Organic charge transport materials which are also known as organic semiconductors are used in opto-electronic devices. They are classified into hole- and electron-transporting materials depending upon the kind of charge carriers transported, but the role of charge transporting materials is not confined within only one function. A number of charge transporting materials have dual functions, for example, charge transport and light emission in organic light emitting diodes (OLEDs), and photogeneration of charge carrier and transport in organic photovoltaic cells (OPVs). Molecules used in charge transporting materials are classified into single crystals, polycrystals, liquid crystals, and amorphous glasses according to their morphologies. Since the device performance is highly dependent on morphology of materials, controlling the morphology is an important factor in material science and practical applications.

This thesis deals with synthesis and application of triarylamine containing polymers. Triarylamine derivatives which are easily oxidized to form stable radical cation species is one of well-known hole-transporting materials. As an amorphous material, they have advantages over crystalline materials in practical application because of their good processability, transparency, and homogeneous properties. The facile chemical modifiability of triarylamine derivatives also makes them as useful building materials for polymer synthesis. Moreover, the incorporation of triarylamine unit into polymer may produce materials with good thermal and mechanical stabilities combined with solution processability.

A new regiocontrolled triarylamine based polymer, Poly[di-5-naphthyl-2-ol]pehnylamine] (PDNPA), having naphthol unis was synthesized by oxidative coupling polymerization. Polymerization in THF using [CuCl(OH)TMEDA] as an oxidant under $O_2$ produced polymers with number-averaged molecular weights up to 11,300. The structure of polymer confirmed by $^1H$ and $^{13}C$ N...