19618-17-8Relevant articles and documents
Synthesis and characterization of highly transparent and hydrophobic fluorinated polyimides derived from perfluorodecylthio substituted diamine monomers
Tapaswi, Pradip Kumar,Choi, Myeon-Cheon,Nagappan, Saravanan,Ha, Chang-Sik
, p. 479 - 488 (2015)
Two new perfluorodecylthio substituted aromatic diamines, namely 2,4-diamino-1-(1H,1H,2H,2H-perfluorodecathio) benzene (DAPFB) and 2,2′-Bis((1H,1H,2H,2H-perfluorodecyl) thio)[1,1′-biphenyl]4,4′-diamine (BPFBD) were synthesized and polycondensed with 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) to produce two new perfluorinated polyimides (PI2 and PI4). The chemical structures of these polyimides were confirmed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy and elemental analysis. Two other polyimides (PI1 and PI3) were also synthesized from 6FDA and analogous perfluorodecylthio unsubstituted diamines to investigate the incorporation effect of perfluorodecylthio group on various physical and chemical properties of the synthesized PIs. Compared with PI1 and PI3, PI2 and PI4 exhibited improved solubility, optical transparency, and hydrophobicity, lower moisture absorption, dielectric constant, and thermo-mechanical stabilities owing to the presence of the perfluorodecylthio side group in the polymer chain. Even though thermo-mechanical properties of PI2 and PI4 (Td5: 413 and 404 °C, Tg: 220 and 209 °C, tensile strength of 101 and 76 MPa, tensile modulus of 1.7 and 1.5 GPa and elongation at break of 8 and 10%, respectively) were reduced in comparison to PI1 and PI3 but still were good enough for most of the practical applications. Most importantly, the presence of the perfluorodecylthio side group in BPFBD considerably reduced the dielectric constant of PI4 to 2.71 which was quite low as aromatic polyimide.
Novel diamine having perfluorodecylthio group, preparation method thereof and fluorinated polyimid film prepared therefrom
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Paragraph 0128; 0130; 0131, (2017/08/26)
The present invention relates to a novel diamine having a perfluorodecylthio group for preparing a novel fluorinated polyimide film, a method for preparing the same, and a novel fluorinated polyimide film having a perfluorodecylthio group obtained from the diamine. The polyimide film obtained from the novel diamine having a perfluorodecylthio group according to the present invention comprises a perfluorodecylthio side group, and thus reduces a CTC effect between polymer chains and improves optical transparency through a steric hindrance effect and an induction effect of the perfluorodecyl side group (electron-donating effect of the diamine), improves solubility, provides increased hydrophobicity and shows improved physical properties, including low water absorbability and a low dielectric constant. Thus, the film according to the present invention can be used advisably instead of the existing polyimide films.COPYRIGHT KIPO 2017
Reduction of nitroarenes to azoxybenzenes by potassium borohydride in water
Liu, Yufang,Liu, Bo,Guo, Ailing,Dong, Zhenming,Jin, Shuo,Lu, Yun
experimental part, p. 3563 - 3568 (2011/06/26)
The synthesis of the azoxybenzenes by the reduction of nitroarenes with reducing agent potassium borohydride in water was reported for the first time. PEG-400 was used as a phase transfer catalyst and could effectively catalyze the reduction. The electronic effects of substituent groups play an important role in determining the reduction efficiencies. Electron-withdrawing substituents promote the formation of the azoxybenzene products, while electron-releasing groups retard the reductions to various degrees depending on the extent of their electron-donating ability.
