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|Title:||High performance polymer films: Part 6, Durability behaviour - Effect of electron affinity and ionization potential of monomers on hydrolytic stability of polymide films|
|Authors:||Khatua, Shankar C|
|Abstract:||Durability behaviour of the polyimide/copolyimide films based on two dianhydrides, pyromellitic dianhydride (PMDA) and 3,3', 4,4' -benzophenonetetracarboxylic dianhydride (BTDA) and two diamines, 4,4'-oxydianiline (ODA) and a proprietary aromatic diamine (P1) has been studied in water, organic solvents and oils, acids and alkalies etc. with the Kapton H film of Du Pont, USA as the reference. The weight gain of the films after immersion in water for 5 days is in the range 0.12 to 81 %. Hydrolytic stability of the Kapton H film in both concentrated and dilute aq. alkali solutions is very poor compared to most of the films under investigation. Its stability in concentrated H2SO4 (98% w/w) is also poor. Hydrolytic stability of any polymide or copolyimide can be predicted by electron affinity-ionization potential (Ea-IP) concept. A polymide film based on a dianhydride of lower Ea and a diamine of lower IP will be more stable hydrolytically than one based on a dianhydride and diamine of higher Ea and IP values.γ-Ray irradiated films are practically unaffected in all respect viz. colour; toughness, flexibility etc. after a maximum dose of 21.60 Mrad which is below the critical dose level of γ-irradiation.|
|Appears in Collections:||IJC-A Vol.42A(11) [November 2003]|
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