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Poly(tetramethylene oxide) (PTHF) oligomers, M" = 650-2000, have been capped with phthalate ester (2) and with phthalic half-ester (3). Properties of the latter are strongly influenced by hydrogenbonding association of carboxylic acid termini. DSC revealed new, high-temperature transitions in the carboxylterminated oligomers (3) which decreased in temperature as PTHF molecular weight increased. Esterterminated oligomers 2 have the rheological properties of simple liquids. Oligomers 3 exhibit melt viscosities and dynamic moduli which decrease sharply at the highest DSC transition temperature but nevertheless exceed those of 2 over the entire range studied. These carboxyl-terminated oligomers exhibit elasticitydominated responses to small strains with a linear viscoelastic region and good recovery to large strain amplitude oscillatory shear. All observations are consistent with formation of large crystalline aggregates of carboxyl-terminated chain ends below the high-temperature DSC transition. Solid-state 13C-NMR suggests the presence of phthalic half-ester end groups in both crystalline and amorphous environments.

Poly(meta1 tetrathiooxalates) (poly(MTT0)) have been synthesized and characterized. For M = Cu, Ni, and Pd and DP = 3-8, the compounds have a high absorption over a broad infrared frequency range and dc electrical conductivities of 1-20 (a cm)-'. Only the Cu and Ni compounds are studied in some detail because of their high conductivities. They have low negative values for thermoelectric power, indicating that the free carriers are negatively charged and highly mobile. Exposure to Iz significantly reduces the conductivity, an effect that is partially reversible. These materials are intrinsic electronic conductors, requiring no doping, and their conductivities are not appreciably decreased upon exposure to ambient environment for several months. Temperature-dependent magnetic susceptibility measurements show appreciable Pauli susceptibility.