Poly Glycol Research Articles

メチルグリコールキトサン，（カルボキシメチル）デキストランおよび硫酸エステル化ポリビニルアルコールからなる高分子電解質複合体膜の透過性 ＩＩ 標題複合体膜によるアルカリ金属イオンの能動輸送と選択透過

多糖類であるメチルグリコールキトザンと(カルボキシメチル)デキストラン,そして合成高分子である硫酸エステル化ポリピニルアルコールの3種類の高分子電解質から合成した水に難溶性な高分子電解質複合体を,キャスト法により成膜した。得られた高分子電解質複合体膜について,アルカリ金属イオンのNa+およびK+に対する能動輸送ならびに選択透過性を検討した。その結果,この膜は,能動輸送および選択透過機能をもっていることが明らかとなった。これは,水素イオン濃度差を騒動力とし,水素イオン濃度の変化にともなう膜の化学的性質の変化,およびキャリヤーの親和性に起因するものと推論される。

Syntheses and properties of urethane prepolymers and their corresponding crosslinked films

AbstractTrimethylol propane (TMP), polyglycol (PG), and toluene diisocyanate (TDI) were reacted in various molar ratios to produce TMP–TDI–PG–urethane prepolymers and then mixed with equivalent isocyanate generator (Desmodur AP‐Stable) in a mixture of m‐cresol and naphtha to give polyurethane varnishes which finally became crosslinked films by the casting method. The mechanical properties and viscoelasticities of the PG‐modified and PG‐free polyurethane crosslinked films and the practicability of magnet wires coated with them were studied in this article. Three different PGs used in this experiment were polyethylene glycol, PEG(#400), polypropylene glycols, PPG(#1000) and PPG(#2000). In the case of adding PEG(#400) for modification, strength at break increased but elongation did not change. Meanwhile, glass transition temperature (Tg) shifted to lower temperature with increasing molar ratio. In the case of adding PPG(#1000) and PPG(#2000) for modification, the samples changed their mechanical properties from hard and brittle to soft and tough. With increasing molar ratios, strength at break initially increased and then decreased gradually, and elongation varied a lot and was consistently contrary to strength at break. Tg occurred at two regions: one at high temperature above 100°C for small molar ratios and the other at low temperature below 100°C for high molar ratios. Besides, for all PG‐modified polyurethane crosslinked films, strength at break showed a local maximum at TMP/TDI/PG = 1/1/0.5, which indicated their homogeneous structures. The molar ratios of PG‐modified urethane prepolymers, which are suitable for manufacturing practical magnet wires according to testing method JIS‐C‐3211, are as follows: TMP/TDI/PPG(#100) = 1/1/0.15–0.35 and TMP/TDI/PPG(#2000) = 1/1/0.10. PEG(#400)‐modified magnet wires were not accepted on the aging test. The properties of crosslinked films of practical magnet wires are generally as follows: strength at break at 200–700 kg/cm2, elongation less than 41%, and Tg at 100–200°C.