Authors: Rengaswamy Jayaganthan, Rohitkumar H. Vora
Abstract: The glass transition temperature (Tg) of Fluoro-Poly(ether-imide) and Fluoro-Poly(either-Imide)/MMY clay Nanocomposites has been investigated by both experiments and Monte Carlo Simulation. It was observed that the (Tg) values of the nanocomposites increases with increase in clay contents.
339
Authors: Rohitkumar H. Vora, Rengaswamy Jayaganthan, Zhida Wang, Ei Thin Thin, Toong Kiang Bang
Abstract: A series of partially fluorinated poly(ether imide) (6F-PEI) and (6F-PEI)/Organosoluble MMT clay nanocomposite were synthesized. XRD data, indirectly confirmed the exfoliation of diamine modified MMT clay at molecular level in the nanocomposite. Thermal properties, and longterm thermo-oxidative stability, thermal degradation kinetics, moisture absorption, chemical resistance of (6F-PEI)s, and nanocomposite films were studied and reported in this paper.
379
Authors: Ying Jie Lei, Jie Ouyang, Mei Ding
Abstract: A convenient method to synthesize 2-(7-fluoro-1H-imidazo[4,5-b]phenazin-2-yl)- phenol derivatives 3a-d with substitute (s) X (X = H, CH2OH, Br, Cl) via the reaction of 7-fluoro- phenazine-2,3-diamine and bisulfite addition products of 2-hydroxy aromatic aldehydes in DMF solution with a yield of 80-85% was developed. Meanwhile, the ultraviolet absorption and the fluorescent spectra of these o-hydroxy derivatives of 1H-imidazo[4,5-b] phenazin were measured in methanol and one fluorescence band with a peak wavelength of 550nm with a Stokes shift around 134-141 nm for 3a-d was observed.
2057
Authors: Jian Yong Lv, Yan Meng, Li Fan He, Teng Qiu, Xiao Yu Li, Hai Qiao Wang
Abstract: A novel fluorine containing epoxy 4-fluoro-4′,4″-diepoxypropoxy triphenyl methane (FDE) was designed and synthesized. The synthesized epoxy was cured by methyl nadic anhydride (MNA) and diglycidyl ether of bisphenol A (DGEBA) was chosen for comparison. Both glass transfer temperature (Tg) and 5% weight loss degradation temperature (Td5%) of cured FDE are over 60°C higher than that of DGEBA. Dielectric constants of the cured FDE at 106 Hz and 107 Hz are 3.09 and 2.91, comparing to 3.50 and 3.24 of the cured DGEBA, respectively. Furthermore, water absorption of the cured FDE is lower than that of DGBEA.
448
Authors: Ping Yu, Yan Wang, Jun Rong Yu, Jing Zhu, Zu Ming Hu
Abstract: A series of addition-type imide oligomer (degree of polymerization: n=1-9) derived from 2,3,3',4'-diphenyl ether tetracarboxylic acid dianhydride (a-ODPA), 3,4'-oxydianiline (3,4'-ODA) and 4-phenylethynylphthalic anhydride (PEPA) was synthesized by thermal imidization. The resultant oligomers were characterized for their chemical architecture, thermal property, and processability. The experimental results showed that oligomers PI-1 and PI-2 had somewhat crystalline phase. PI-4, PI-6 and PI-9 exihibited high solubility in solvents. These imide oligomers have a very low melt viscosity, and thus provide wide processing window by the rheological behaviors. Furthermore, the cured polyimides exhibited excellent thermal stability under N2 atmosphere. The temperatures of 5% weight loss in N2 atmosphere were all above 524°C.
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