Preparation and Properties of Optically Clear Poly[(Arylenedioxy)(Diphenylsilylene)]s and Poly[(Alkylenedioxy)(Diphenylsilylene)]
Several types of poly[(arylenedioxy)(diphenylsilylene)]s and poly[(alkylenedioxy)(diphenylsilylene)] were synthesized from various diols and dichlorodiphenylsilane by the step polymerization method. The thermal properties, solubility in organic solvents and optical properties of the obtained polymers were investigated by focusing on the chemical structures of their repeating structural units. The weight-average molecular weight ( Mw) of the obtained polymers based on polystyrene ranged from 43000 to 194000. High molecular weight, ductile materials with a high degree of optical clarity were obtained. These polymers display glass transition temperatures ( Tg) between 96 and 130°C. The obtained poly[(arylenedioxy) (diphenylsilylene)]s and poly[(alkylenedioxy)(diphenylsilylene)] were soluble in chloroform and toluene. The refractive index ( nd) was 1.64 for a biphenol-based poly[(arylenedioxy)(diphenylsilylene)] and 1.61 for a bisphenol-A based poly[(arylenedioxy)(diphenylsilylene)]. The poly[(arylenedioxy)(diphenylsilylene)]s and poly[(alkylenedioxy)(diphenylsilylene)] display very low birefringence (Δ n) between 0.0005 and 0.0022. The 70 μm thick film transmission of bicyclohexanol-based poly[(alkylenedioxy)(diphenylsilylene)] was 91% at a 350 nm wavelength.