Papers by Keyword: Side Chain

Abstract: Waterborne side-chain fluorinated polyurethanes were prepared from fluorine-containing polyether polyol, N210, isophorone diisocyanate (IPDI) as main materials through self-emulsified method. The factors on FWPU, including the particle size and distribution, solid content, the acid and alkali resistant properties of emulsion film, were investigated. The results indicated that the particle size of fluoronated polyurethane dispersion was small, and dispersion had good stability. The emulsion film had better chemical resistant properties.

Abstract: High molecular weight, readily soluable copolymer was prepared from 9,9-di (2-thienyl-hexyl) fluorene (TF) 2,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9,9-di octyl fluorene and narrow band gap comonomer 2,3-dimethyl- 5,8-(5-bromo)-dithien-2-yl-quinoxalines (DTQU) using pallad- ium catalyzed Suzuki coupling methods. To compare the copolymer to this without thiophene in the C9 side chain of fluorene, the copolymer from DOF and DTQU was synthesized. The electrochemical, optical and photovoltaic properties of the copolymers were studied. The absorption spectra of the copolymers measured in thin films display two absorption peaks. The power conversion efficiency achieved in the device configuration ITO/PEDT/FT- DTQU:PCBM (1:2)/Al is 0.85% with open-circuit voltage (Voc) 0.8V. Further improvement by manipulating polymer/electrode interface and further investigation of more polyfluorene copolymers with narrow band gap aryl-hetero cycle units on the side chain is in progress.

Abstract: This paper demonstrated acylation of cellulose with long chain fatty acid and internally plasticized cellulose films obtained by casting. The degrees of substitution (DS) and molar yields of fatty acid, Ts-Cl amounts and reaction time, and as well as the property of final products were studied. Partially derivative celluloses presented glass transition compared to starting cellulose. However, thermal behaviors of the internally plasticized esters with different DS were similar. Dynamic mechanical thermal analysis (DMTA) in tension mode revealed separate relaxations, denoted α and β, corresponding to the glass transition and side-chain melting processes, respectively. According to this, these longer chain esters (LCCEs) showed promise as internally plasticized cellulose films because the supermolecular structure of cellulose was significantly changed with the introduction of longer substituent.

Abstract: A serial of polyfluorene copolymers have been developed by covalently attaching thiophene units to the side chain of polyfluorene with an alkyl spacer by means of Pd-catalyzed Suzuki coupling reactions. The electrochemical, photophysical and photovoltaic properties of the copolymers were studied. The absorption spectra of the copolymers measured in thin films display two absorption peaks. The power conversion efficiency achieved in the device configuration ITO/PEDT/ PFO-FT-DBT: PCBM (1:2)/Al is 0.83% with open-circuit voltage (Voc) 0.75V. Further investigation of more polyfluorene copolymers with narrow band gap aryl-hetero cycle units on the side chain is in progress.

Abstract: Typical conductive polymers of poly(3-alkylthiophenes) were synthesized by oxidative polymerization. Polythiophene with no side chain was also electrolyticaly polymerized. Alkyl side chains were CnH2n+1 with n=4, 6, 8, 12. The regioregularity with the HT linkage was larger than 99% based on NMR analysis. We have evaluated the effect of side chain size on the thermoelectric properties of Seebeck coefficient and electrical conductivity. The results were as follows: 1) Seebeck coefficient decreased with an increasing electrical conductivity. 2) High Seebeck coefficient >1mV/K was observed at low electrical conductivity <10-2S/cm. 3) Small side chains, especially no side chain caused higher thermoelectric properties of polythiophene series.