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The crystallization behavior of a newly developed polyvinyl alcohol with 1,2-diol side-chains (DPVA) was investigated for different 1,2-diol side-chain, magnesium acetate, and sodium acetate contents. Crystallization by stepwise cooling, isothermal and non-isothermal crystallization (the actual cooling process in melt molding) experiments were conducted. Upon crystallization analysis by stepwise cooling, the end surface energy of DPVA increased as the 1,2-diol side-chain content was increased. The isothermal crystallization process exhibited longer half crystallization times at high 1,2-diol side-chain and magnesium acetate contents. Upon Kissinger analysis of the non-isothermal crystallization results, the effect of the acetate salts was found to be smaller than that for isothermal crystallization, while the smaller number of repeating units in the lamellar structure, reflecting a higher side-chain 1,2-diol content, resulted in a smaller activation energy for DPVA crystallization. In addition, analyses by the Ozawa method and the Kissinger Plot suggested possible changes in the mode and dimension of the crystal growth of DPVA.

Purpose To preliminarily examine whether solubility of water-soluble polyvinyl alcohol (PVA) microspheres in blood plasma changes in proportion to their degrees of saponification. The study also examined their feasibility as a temporary embolic agents in the pig renal artery. Materials and Methods Three types of PVA microspheres with the degrees of saponification of 97 mol% (S97), 98 mol% (S98), and 99 mol% (S99) were prepared. Seven kidneys in seven miniature pigs were embolized and divided into three groups so there would be at least two kidneys for each type of PVA. One animal in each group was euthanized immediately after angiography at 3 hours after embolization and the other one at 7 days after. In addition, one animal embolized with S99 microspheres was euthanized at 21 days after embolization. Results With S97 microspheres, the vascular network had recovered to the preembolic state by 3 hours after embolization. With S98 microspheres, blood flow in the third-order branch had been restored in the same period. With S99 microspheres, the second- and lower order branches remained occluded until 21 days. Histopathologic specimens harvested at 3 hours revealed only a trace of PVA for S97 microspheres. With S98 microspheres, the vascular lumen was still found to be filled with PVA gel. With S99 microspheres, swollen microspheres densely filled the vascular lumen even on day 21. Conclusions Dissolution process in vitro and the duration of arterial occlusion in vivo were possibly related to the degree of saponification of PVA. This result may support feasibility of PVA microspheres as a temporary embolic agent.

Alkaline polymer gel electrolytes mainly with modified polyvinyl alcohol (PVA) have been prepared for an electric double layer capacitor (EDLC). Their electrochemical characteristics were evaluated by impedance spectroscopy and constant-current charge/discharge measurement. The prepared gel electrolyte film with KOH exhibits excellent flexibility and an ionic conductivity of about 7×10−2 S cm−1 at 298 K. The gel electrolyte EDLC shows comparable discharge capacitance to that for EDLC containing a conventional aqueous electrolyte. These results suggest that the gel electrolyte based on the modified PVA is promising material for use in EDLC.

アセトアセチル（AA）化度を変えたAA化PVAと部分ケン化一般PVAを用いて，ジメチルスルホキシド（DMSO）を溶媒に用いた場合のpMDIとの反応性について水を溶媒に用いた場合と比較した。AA化PVAとpMDIとの反応性や架橋形成について以下の結果が得られた。溶媒にDMSOを用いた場合では，硬化フィルムのゴム状平坦部におけるE′値から算出した架橋密度はE″ピーク温度のずれから算出した架橋密度とほぼ同じ値となったが，溶媒に水を用いた場合では，前者の値は後者の値よりも高くなった。DMSO溶媒系硬化フィルムの重量膨潤度は，一般に水溶液系のフィルムよりも小さかった。またAA化PVAフィルムの重量膨潤度は一般PVAのそれらよりも小さく，これらのことからDMSO系の方が水系よりも重量膨潤度が小さく，またAA化PVAの方がフィルムの架橋密度が高くなることが示唆された。

Title annulenes were synthesized by Wittig reaction of cyclohepta-1,3,5-triene-1,6-dialdehyde or its vinylogous dialdehydes with 5-methylpenten-2-yn-4-yltriphenylphosphonium bromide, followed by intramolecular oxidative couplings of the resulting acyclic compounds, and they proved to be diatropic or paratropic, corresponding to the number of peripheral π-electrons.

The title annulenes (4a–d) have been synthesized by a Wittig reaction of cyclohepta-1,3,5-triene-1,6-dicarbaldehyde (1a) or its vinylogous dialdehydes (1b–d) with 3-methylpent-2-en-4-ynyltriphenylphosphonium bromide (2), followed by intramolecular oxidative coupling of the resulting acyclic compounds. They proved to be diatropic or paratropic, depending on the number of peripheral π-electrons. The related [1,3]cyclophanpolyenediynes (11), (14), (17), (19), (21), and (23) were prepared by a double Wittig reaction of 3-methylpent-2-en-4-ynal (8) and/or its vinylogous aldehydes (9) and (10), with 1,3-bis(triphenylphosphoniomethyl)benzene dibromide (7), followed by intramolecular oxidative coupling of the resulting acyclic compounds. Their properties are compared, on the basis of 1H n.m.r. and electronic spectral results, with those of tetradehydromethanoannulenes.

Reductive couplings of the vinylogues of cyclohepta-1,3,5-triene-1,6-dicarbaldehyde with a low-valent titanium reagent afforded the corresponding monomeric or dimeric products, i.e. singly bridged or doubly bridged annulenes in most cases. These annulenes showed diatropicity or paratropicity, depending on the number of peripheral conjugated π-electrons. The 1H n.m.r. spectra of the methanoannulenes showed a larger temperature-dependency than those of the closely related tetradehydromethanoannulenes, reflecting the lower planarity and the larger conformational mobility of the molecular skeleton in the former compounds.

Reductive coupling of 1, 6-bis(2-formylvinyl)cyclohepta-1, 3, 5-triene with a low-valent titanium reagent afforded a paratropic bismethano [24] annulene.

Reductive couplings of the vinylogues of cyclohepta-1,3,5-triene-1,6-dicarbaldehyde with a low-valent titanium reagent afforded the corresponding monomeric or dimeric products, i.e. singly bridged or doubly bridged annulenes in most cases. These annulenes showed diatropicity or paratropicity, depending on the number of peripheral conjugated π-electrons. The 1H n.m.r. spectra of the methanoannulenes showed a larger temperature-dependency than those of the closely related tetradehydromethanoannulenes, reflecting the lower planarity and the larger conformational mobility of the molecular skeleton in the former compounds.

The title annulenes (4a–d) have been synthesized by a Wittig reaction of cyclohepta-1,3,5-triene-1,6-dicarbaldehyde (1a) or its vinylogous dialdehydes (1b–d) with 3-methylpent-2-en-4-ynyltriphenylphosphonium bromide (2), followed by intramolecular oxidative coupling of the resulting acyclic compounds. They proved to be diatropic or paratropic, depending on the number of peripheral π-electrons. The related [1,3]cyclophanpolyenediynes (11), (14), (17), (19), (21), and (23) were prepared by a double Wittig reaction of 3-methylpent-2-en-4-ynal (8) and/or its vinylogous aldehydes (9) and (10), with 1,3-bis(triphenylphosphoniomethyl)benzene dibromide (7), followed by intramolecular oxidative coupling of the resulting acyclic compounds. Their properties are compared, on the basis of 1H n.m.r. and electronic spectral results, with those of tetradehydromethanoannulenes.