Preparation And Properties Of Broadband Functional Polyacetylenes

Polyacetylenes as well-known conjugated polymers possess excellent time response and electronical conductivity, and also exhibit novel optical, electronic and biological properties when appropriate substituents or pendants are appended to the polyene backbones. Squaraine dyes have attracted great interesting owing to their unique photochemical and photophysical properties, which make them applied to a variety of field such as organic solar cells, non-linear optics, sensors for metal ions, and biological probe. In order to prepare functional polyacetylenes with fast time response and broad absorption wavelength, two novel polyacetylenes with squaraine group were designed and synthesized in this dissertation, and their structures and properties were characterized and evaluated. The content of the dissertation are as follow.1. The development, synthesis method and latest application of functional polyacetylenes were reviewed in detail.2. Three monomer molecules 6-ethynyl-2-methyl quinoline (EMQ),4-propynyloxy-4’-nitryl azobenzene (NPA),4-ethynylstyryl-4’-butoxy diphenylethene (BES) were designed and synthesized. The homopolymers poly(EMQ), poly(NPA) and poly(BES) were prepared by solution polymerization using metal catalyst. Their structures and properties were characterized and evaluated by elemental analysis (EA), fourier transform infrared spectoscopy (FT-IR), nuclear magnetic resonance (’H-NMR), differential scanning calorimetry (DSC), thermo gravimetric analyzer (TGA), ultraviolet and visible spectroscopy (UV-vis). The results show that the absorption intensity of homopolymers are enhanced compared to monomers. At the same time, the thermal performance of homopolymers are also significantly improved.3. The azo and diphenylethylene acetylene monomers (NPA and BES) were copolymerized with quinoline substituted acetylene monomer (EMQ) respectively. The controllable preparation of soluble copolymers poly(EMQ-eo-NPA) and poly(EMQ-co-BES) were achieved by varying feed ratio of monomers. The optical absorption of resultant copolymers can be effectively adjusted. The their structures and properties were characterized and evaluated by FT-IR, ’H-NMR, DSC, TGA, UV-vis. The results dispaly that the solubility of copolymers poly(EMQ-co-NPA) and poly(EMQ-co-BES) were improved in common solvent such as (THF), compared to poly(EMQ), which is conducive to the following reaction. In addition, the wavelength and intensity of UV absorption peak for copolymers poly(EMQ-co-NPA) and poly(EMQ-co-BES) are enhanced, which is beneficial to realization of broadband absorption.4. The functional polyacetylenes with broad absorption wavelength were prepared by squaraine functionalization of the above poly(EMQ0.8-co-NPA0.2) and poly(EMQ06-C0-BES0.4). The controllable preparation of functional polyacetylenes with UV-Vis-NIR absorption were achieved by Uv-vis tracking dynamic spectrum technology. Their molecular structures and properties were characterized and evaluated by FT-IR,1H-NMR and UV-Vis. The mechanism of broadband were researched by Uv-vis tracking dynamic spectrum technology.