Three acrylic monomers bearing 4′‐dialkylamino‐4‐nitro‐stilbene and ‐azobenzene dyes have been synthesized. The monomeric dyes were homopolymerized and copolymerized with methyl methacrylate using a free radical initiator to produce polymers useful for nonlinear optics. Comparison of the solubility and molecular weight distribution data between stilbene‐ and azobenzene‐containing polymers indicated that some crosslinking occurred during polymerization with the stilbene monomers, presumably through the internal double bond in the dye. The dye‐containing homopolymers exhibit liquid crystallinity. Some interaction among the pendant dyes was detected by visible spectroscopy.
Mixtures of five-arm star polystyrene with an organoclay spontaneously formed exfoliated nanocomposites when annealed, validating a recent theoretical prediction by Singh and Balazs (Polym. Int. 2000, 49, 469.). An analogous linear polystyrene sample produced only an intercalated morphology under the same conditions. The nanocomposite morphologies were characterized by X-ray diffraction and transmission electron microscopy. These results suggest a general strategy for forming exfoliated nanocomposites in commodity polymers via melt compounding.
The title polymer has been synthesized in moderate molecular weight by the self-condensation of sodium 4-halobenzenesulfimate at 175 "C in dimethylsulfoxide. The use of a small amount of 4-fluorophenyl sulfone served to greatly increase the yield of polymer, presumably by acting as an initiator for a chain-type polymerization. The title polymer is highly crystalline (>85%) and poorly soluble in all solvents attempted. The number-average degree of polymerization was estimated to be 10-16 by elemental analysis. No thermal transitions below 500 "C were detected by DSC. The polymer exhibited extremely high and unusual thermal stability when studied by TGA; the onset of significant mass loss occurred at 517 "C in nitrogen and at 555 O C in air. The polymer was characterized by IR and solid-state 13C NMR spectroscopy and by X-ray diffraction. Analogous model compounds for the trimer and tetramer were prepared and used to confirm the structure of the polymer.
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