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The influence of a variety of factors on the photomechanical output of azo-CP2- xx systems is studied, primarily focusing on a sample with a higher crosslink density (30 mol%) and two new, structurally related crosslinked polyimides with modified backbone flexibility/rigidity. This work elucidates the strong coupling between geometrical considerations (reciprocal aspect ratio of cantilever) and the visualized mechanical response (e.g., flexural-torsional response of a cantilever). [ABSTRACT FROM AUTHOR]

A series of poly(arylene ether)s, (PAEs), carrying a pendant diphenyl phosphoryl group were prepared via the nucleophilic aromatic substitution (NAS) reactions of 3,5-difluorotriphenylphosphine oxide, 6. The difluoro monomer 6 was synthesized via two-step reaction sequence and subsequently characterized by 1H, 13C, 19F, and 31P NMR spectroscopy, GC/MS, and elemental analysis. The reactivity of the electrophilic sites in 6, activated by only a diphenylphosphoryl group located in the meta-position, in 6 was probed via NMR spectroscopy and model reactions and was determined to be sufficient to undergo typical NAS reactions. High molecular weight, amorphous, organic soluble poly(arylene ether)s, bearing a pendant diphenylphosphoryl group, were prepared via the reaction of 6 with a variety of bis-phenols under typical NAS conditions. The poly(arylene ether)s were characterized for structure via the use of 1H, 13C, and 31P NMR spectroscopy while their thermal properties were evaluated using DSC and TGA analysis. The glass transition temperatures ( Tg) of the synthesized PAEs ranged from 143 to 175 °C, while their 5% weight loss temperatures ranged from 467 to 510 °C under nitrogen and from 470 to 526 °C in air. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 [ABSTRACT FROM AUTHOR]