Tomoyuki Itaya

Ionic conductivity of complexes of novel multiarmed polymers with phosphazene core and LiClO4

Novel multiarmed polymers with ethylene oxide units, [(- CH 2 CH 2 0 ) n -: 7, n = 3; 8, n = 7.2; 9, n = 11.8, and 12, n = 11.8) were prepared from the reaction of polyethylene glycol monomethyl ethers with acid chlorides of hexakis ( 3,5-dicarboxy-phenoxy)- (6) and hexakis(4-carboxyphenoxy)cyclotriphosphazenes (11) and conductivities of their Li + salt complexes were investigated. The glass transition temperatures of the salt-free polymers are in the temperature range -59 to -54°C, indicative of a high degree of reorientational mobility of the arms. When LiClO 4 was added to the multiarmed polymers, the T g values raised monotonically. The extent of T g elevation was affected by the length of arms and the number of oxygen atoms around cyclotriphos-phazene core and increased in the order 7 > 8 > 12 > 9. The conductivities increased in the order 9 > 8 = 12 > 7 and the maximum conductivities of 4.0 x 10 -5 S/cm at 30°C and 6.0 x 10 -4 S/cm at 90°C have been achieved for the 9-Li + complex with Li + /O = 0.03. Interestingly, the conductivity of 9-Li + complexes at constant reduced temperatures increased in the whole concentrations of LiClO 4 examined (Li + /O = 0.01-0.2), although the degree of increase in conductivity above Li + /O = 0.06 became small. From the behaviors of T g and the conductivity of multiarmed polymer-LiClO 4 complexes, it appears that the conductivity is governed by relative concentrations of inter-and intramolecular complexes in the polymer matrix. The influence of structural change of the comb-shaped to multiarmed polymers on the conductivity is described.

Synthesis and thermal properties of polyesters from cyclotriphosphazene

Abstract Polyesters containing cyclotriphosphazene units have been prepared by phase transfer catalyzed two-phase polycondensation and direct polycondensation. The polycondensation of the acid chloride of ( trans -2,4-dicarboxyphenoxy-2,4,6,6-tetraphenoxy)cyclotriphosphazene ( trans -CPP) and bisphenol A (BA) in the presence of benzyltriethylammonium chloride (BTEAC) as phase transfer reagent gave a polyester with a molecular weight of 22,000, whereas only oligomer was obtained by the polycondensation of the cis -isomer with BA. The result indicates that the trans -isomer is favorable to effective growth of the polyester. The direct polycondensation using SOCl 2 /pyridine and TsCl/DMF, however, resulted in the formation of low molecular weight polyesters even though trans -CPP was used. In the copolycondensation of BA with acid chlorides of trans -CPP and terephthalic acid, copolymers with molecular weights of 24,000-13,000 were obtained. The homopolyester prepared from trans -CPP and BA exhibited a significantly low glass transition temperature of 65 °C, and the copolymers had glass transition temperatures in the range 220-91 °C, depending on the contents of trans -CPP units. Thermogravimetric analysis showed that the homopolyester was stable up to 390 °C in a nitrogen atmosphere, and the char yield of copolyester with 5.5 mol.% of trans -CPP unit was 36% at 600 °C, which was seven times higher than that of the polyester without cyclotriphosphazene units. The presence of cis -CPP units in the polyesters lowered the initial decomposition temperatures, but not char yields.

Construction of hairy-rod coordination polymers with lamellar structure by self-assembling of hexakis(4-pyridylmethoxy)cyclotriphosphazene and silver alkylsulfonates

Abstract The supramolecular self-assembly of hexakis(4-pyridylmethoxy)cyclotriphosphazene (PyPN) and silver alkylsulfonates AgSO3CnH2n+1 (n=12, 14, 16, 18) gave a new type of hairy-rod coordination polymer. Elemental analysis, FT-IR, differential scanning calorimetry and X-ray diffraction techniques indicated that the coordination polymers with an alternating sequence of one PyPN and three Ag+ ions bearing alkylsulfonate anions as side chains are formed to give a hairy-rod structure. The hairy-rod polymers with alkyl side-chains of AgC14 (n=14), AgC16 (n=16) and AgC18 (n=18) are organized in lamellar structures, where the alkyl chains tilted with respect to the polymer backbone by ca. 40° are interdigitated with each other. On the other hand, the coordination polymer with an alkyl side-chain of AgC12 (n=12) did not distinctly form the lamellar structure due to the relatively short alkyl chains. The effects of alkyl side-chain length on the formation of lamellar structure of the coordination polymers are described.

Polymerization of styrenes with pendant aminophosphazenes and fluorescence behaviors of their Eu3+ complexes

Abstract Radical polymerizations of novel styrenes with pendant penta(3-dimethylaminopropylamino)-(SPDAP) and penta(2-dimethyl aminoethoxy)cyclotriphosphazene (SEAP) in various solvents and the fluorescence behavior of complexes of Eu3+ with these cascade materials were studied. The conversion of SEAP increased on going from THF to ethanol, whereas the conversion of SPDAP in ethanol showed the lowest value. The application of the Kamlet-Taft equation to the conversion suggested that the polymerization of SPDAP and SEAP is primarily affected by the hydrogen bond interaction. 13C NMR spectra of SEAP showed that the peak of the β-carbon in the vinyl group shifted downfield as the conversion increased. This suggests that the interaction between the monomer and solvents brings about a change of polymerizability of SEAP. A similar downfield shift was observed for SPDAP in ethanol, suggesting that SPDAP also has a high polymerizability. The inherent viscosities of poly(SEAP) and poly(SPDAP) in ethanol were found to be considerably higher than those in THF. This result and the kinetic treatment of polymerization suggest that the side arms on the phosphazene ring in ethanol are expanded due to the hydrogen bond interactions with the solvent, and that the propagation is sterically hindered, especially for the polymerization of SPDAP with relatively long side arms. This might be responsible for the low conversion observed for the polymerization of SPDAP in ethanol. When Eu31 ions were added to SPDAP, a significant increase in fluorescence intensity of Eu3+ was observed. The plot of fluorescence intensity vs the concentration of SPDAP suggests the formation of a 2:1 SPDAP-Eu3+ complex. For the polymer-Eu3+ complex, a similar increment of the intensity was observed. From the chemical shifts of side arms in the monomer-Eu3+ complex, the structure of the complex is discussed.

Polymeric Hydrogen-Bonded Supermolecules by Self-Assembling of Hexakis(4-Pyridylcarbinoxy) Cyclotriphosphazene and Dicarboxylic Acids

Abstract Hexakis(4-pyridylcarbinoxy)cyclotriphosphazene (PyPN) and terephthalic acid (TPA) self-assembled into polymeric supermolecules through hydrogen bonding between carboxyl and pyridyl groups. Two supermolecular self-assemblies were obtained: crystals 1 composed of 2:1 TPA/PyPN from DMF/ DMSO, and crystals 2 composed of 3:1 TPA/PyPN from DMF. The former is monoclinic, space group C2/c with a = 26.029 A, b = 7.854 A, c = 28.073 A, β = 116.47°, V = 5138 A3, and Z = 4. The structure was defined to R = 0.064 based on 2832 data, I>1.5 σ(I). The X-ray analysis revealed that PyPN is joined with two TPA molecules through hydrogen bonding to form a polymeric assembly. The self-assembly obtained from DMF seems to take a cylindricalshaped structure, i.e., all of pyridyl group in PyPN participate in the formation of the assembly, as evidenced by elemental analysis, FT-IR spectroscopy and X-ray diffraction data. These results and the role of the solvent are described.