Naphthalene-containing polymers

The difficulty with interpretation of quenching by small molecules is determination of the true number of contacts between an individual chain and the quencher. Among the assumptions made in arriving at a value for u from small-molecule quenching studies are an isotropic quencher distribution and an educated guess of the interaction distance between donors. Values of u obtained for naphthalene-containing polymers by the two methods differ substantially, from u = 100-300 s" - for the quenching experiments (10,11,16,17) to u =... 

The most important condition which should be tested experimentally is that of overlap of emission bands. It has been shown that excimer overlap with monomer emission is significant for polystyrene (5) thus any determination of relative excimer/monomer yields must make allowance for this factor. This correction is large when the area of excimer peak is much greater than that of the monomer, a situation which prevails for solutions of polystyrene. Examination of emission spectra of naphthalene containing polymers indicates that when excimer is formed the emission overlaps to a... 

The results presented above may be compared with previous studies on these polymers. It has been suggested that more than one spectrally distinct excimer species may exist in some naphthalene-containing polymers (6,22). Analyses of the spectral surfaces for the polymers studied in this work clearly indicate that only one spectrally distinct monomer and one excimer species contribute to emission. Phillips and co-workers (3,23) also found that the monomer fluorescence decay from PACE requires a minimum of three exponential terms to provide adequate fitting. They explained their results on the basis of a kinetic model involving two temporally distinct excited monomers (M3, M2 ) which can form the excimer (D ) as outlined in Scheme 1. Reverse dissociation of the excimer was also considered important. 

Gao LJ, Xiao M, Wang SJ, Meng YZ (2008) Thermally stable poly (propylene carbonate) synthesized by copolymerizing with bulky naphthalene containing monomer. J Appl Polym Sci 108 1037-1043... 

Other nitrogen containing polymers which have been subjected to thermal decomposition studies include aromatic polyester imides containing 2,7-bis(4-aminobenzoyloxy) naphthalene groups [16], poly-4-vinylpyridine [17], poljmrethanes [18], polybutyl cyanoacrylate [19], and polypropyl acrylate [20]. 

Aromatic crystalline polyesters, including PET, PBT, poly(ethylene naphthalene) (PEN) and poly(trimethylene terephthalate) (PTT), are typically considered to be engineering polymers, thus many of the examples of aromatic polyester blends will be discussed in Section 4.6. Polyesters exhibit the ability of ester exchange in blends with structurally different polyesters, leading to block copolymer formation during thermal exposure. With hydroxyl containing polymers, such as the polyhydroxyether of Bisphenol A (Phenoxy PHE) and poly(4-vinyl... 

Aliphatic 42) and aromatic 131, 132) tetracarboxylic acids have been polymerized with tetravalent metal and metalloidal salts. Low molecular weight prod ucts that decomposed at less than 200°C were obtained by reaction of silicon tetrachloride with aliphatic tetraacids. Pyromellitic acid and 2,3,6,7-naphthalenetetracarboxylic acid are converted to polymers by reaction with metal salts in water at 100°C (IX-32). The thermal stabilities of thorium-containing products were compared. The naphthalene-derived polymer was found to be less stable (360°C d) than the pyromellitic polymer. This result was attributed to the possibility that in thorium pyromellitate the thorium coordination shell is completed exclusively by carbonyl groups of neighboring chains, whereas in the naphthalene salt, water occupies two of the coordination sites of thorium. Uranium salts were less stable thermally than the thorium analogs 131). 

The main chain of these polymers contains, as the principal component, five- or six-membered heteroaromatic rings, ie, imides, which are usually present as condensed aromatic systems, such as with benzene (phthalimides, 3) and naphthalene (naphthalimides, 4) rings. 

Although the sulfone activated biphenyl and the ketone activated naphthalene moiety for the displacement polymerization have been reported by Attwood et al. [11], these were rediscovered by Cummings et al. [12] and Hergenrother et al. [13], respectively, for the synthesis of poly(aryl ethers). Recently, Singh and Hay [14] reported polymers containing 0-dibenzoyl benzene (1,2,3) moiety by reaction between bis(O-fluorobenzoyl) benzene or substituted benzene with bisphenates of alkali metal salt in DMAC as follows ... 

Addition of styrene to a green solution of naphthalene" Na+ in tetrahydrofuran leads to an instantaneous change of color from green to red. Styrene polymerizes rapidly and quantitatively within a few seconds, and when the reaction is completed, addition of water converts the red solution of polystyryl carbanions into colorless solution of polystyrene. After precipitation of the polymer it was shown spectroscopically25 that the residual solution contains an amount of naphthalene equal to that used in the preparation of the initiating catalyst. This observation confirms the proposed mechanism of initiation of the polymerization. 

Homopolymers and copolymers from amido-sulfonic acid or salt containing monomers can be prepared by reactive extrusion, preferably in a twin screw extruder [1660]. The process produces a solid polymer. Copolymers of acrylamide, N-vinyl-2-pyrrolidone, and sodium-2-acrylamido-2-methyl-propane sulfonate have been proposed to be active as fluid loss agents. Another component of the formulations is the sodium salt of naphthalene formaldehyde sulfonate [207]. The fluid loss additive is mixed with hydraulic cements in suitable amounts. 

Aromatic poly(aryl ether ketone)s containing 1,4-naphthalene moieties were prepared by the reaction of a bisphenol and 2 in the presence of potassium carbonate in DM Ac at 160°C as depicted in Scheme 3. A typical polymerization was carried out as follows To a 100-ml round-bottom flask was added 8.32 g (O.OlOmol) of2, 3.36g (O.OlOmol) of4,4 -(hexafluoroisopropylidene) diphenol, 51.2 g ofDMAc, and 3.1 g (0.022 mol) of potassium carbonate. The mixture was heated to 160°C with stirring under nitrogen for 18 h. The mixture was allowed to cool to room temperature. The polymer was precipitated by pouring the reaction mixture into a blender containing about 100 ml of water, filtered, washed three times with water and dried to yield 8.1 g (92% yield) as a white powder. 

Six novel fluorinated poly(aryl ether)s containing 1,4-naphthalene moieties were synthesized in high yield using 2,2-bis[4-( 1 -naphthoxy)phenyl]hexafluoro-propane (1). Oxidative coupling ofl yielded a polymer with high 7, low moisture absorption, and low dielectric constant that could be cast into flexible films. The low dielectric constant and low moisture absorption of 6FNE may make it useful as a dielectric insulator in microelectronics applications. 

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