Tetrasubstituted carbon containing two different halogen substituents was constructed in a single-step operation by utilizing the carbene-like reactivity of dioxaphospholene through the tandem reaction of electrophilic and nucleophilic halogenating reagents. It was crucial to devise non-dealkylatable phosphoramidite, which enabled the efficient formation of geminal chlorofluorides from various 1,2-diketones with (PhSO2)2NF and n-Bu4NCl. In addition, selective functionalization of the chlorine substituent was demonstrated, and the absence of halogen scrambling was confirmed.

2,4-Bis-(3,4-dicarboxyphenylcarboxyethoxy)-1-(2,2-dicyanovinyl)benzene dianhydride (4) was prepared and reacted with 4,4 0 -oxydianiline, 4,4 0 -diaminobenzanilide and 4,4 0 -(hexafluoroisopropylidene)dianiline to yield novel Y-type polyimides 5-7 containing 2,4-dioxybenzylidenemalononitrile groups as nonlinear optical (NLO) chromophores, which constitute parts of the polymer backbone. The resulting polyimides 5-7 are soluble in polar solvents such as dimethylsulfoxide and N,N-dimethylformamide. Polymers 5-7 showed a thermal stability up to 330 8C in thermogravimetric analysis thermograms with T g values obtained from differential scanning calorimetry thermograms in the range 179-194 8C. The second harmonic generation (SHG) coefficients (d 33 ) of poled polymer films at the 1064 nm fundamental wavelength were around 5.56 3 10 À9 esu. The dipole alignment exhibited exceptionally high thermal stability even at 20 8C higher than the glass-transition temperature there was no SHG decay below 215 8C because of the partial main-chain character of polymer structure, which is acceptable for NLO device applications. V V C 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: [3078][3079][3080][3081][3082][3083][3084][3085][3086][3087] 2008

A hydrophilic fouling-resistant poly(vinyl alcohol) (PVA) based polymer was synthesized by the etherification of PVA with monochloroacetic acid under alkaline conditions, and the polymer, PVA-OCH 2 COONa, was subsequently applied to modify a poly(-vinylidene fluoride) (PVDF) membrane to both enhance the hydrophilicity and provide fouling resistance. The successful etherification was confirmed by 13 C-NMR and attenuated total reflectance-Fourier transform infrared spectroscopy, whereas the synthesized polymer was shown by differential scanning calorimetry analysis to have an improved thermal stability over PVA. The physicochemical properties of the surfaces of the modified PVDF membranes were investigated with various analytical tools, including field emission scanning electron microscopy, atomic force microscopy, and contact angle analysis. Fouling tests with bovine serum albumin showed the PVA-OCH 2 COONa modified PVDF membrane to have both a higher pure water flux and a retarded decline in flux over the filtration period compared with the PVA-coated PVDF membrane. This study demonstrated that the modification of PVDF membranes with PVA-OCH 2 COONa could be an efficient method for enhancing their fouling resistance.

No abstract

A novel Y-type poly [iminocarbonyloxyethyl-5-methyl-4-{2-thiazolylazo-4-(1,2,2-tricyanovinyl)}resorcinoxyethyloxycarbonylimino-(3,3 0 -dimethoxy-4,4 0 -biphenylene)] 4 containing 5methyl-4-{5-(1,2,2-tricyanovinyl)-2-thiazolylazo}resorcinoxy groups as nonlinear optical (NLO) chromophores, which constitute part of the polymer backbone, was prepared and characterized. Polyurethane 4 is soluble in common organic solvents such as acetone and N,N-dimethylformamide. It showed a thermal stability up to 250 C in thermogravimetric analysis thermogram and the glass-transition temperature (T g ) obtained from differential scanning calorimetry thermogram was around 118 C. The second harmonic generation coefficient (d 33 ) of poled polymer films at 1560 nm fundamental wavelength was around 8.43 Â 10 À9 esu. The dipole alignment exhibited a thermal stability even at 12 C higher than T g , and there was no SHG decay below 130 C due to the partial main-chain character of the polymer structure, which is acceptable for NLO device applications.