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Effects of Gamma Radiation on Various Polyimides
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AbstractFour polyimides (PIa‐PId) containing 4,4′‐hexafluoroisopropylidene‐bisphthalic anhydride (6FDA) units in the backbone were prepared via one‐step synthesis. The effects of different doses of gamma radiation from a cobalt‐60 source are studied. The irradiated and the unirradiated polyimides are characterized by using tensile strength, infrared (IR), viscosity, differential scanning calorimeter (DSC), and gel permeation chromatography (GPC). All polyimides show the increase of tensile strength and elongation at low doses (>350 Mrad). The molecule weights decrease as the irradiation doses increase. All samples showed a drastic degradation of the mechanical and thermal properties at doses above 1400 Mrad. Samples irradiated at a dose of 2800 Mrad were completely brittle. The major difference of the radiation effect of the polyimides depends largely on their structural differences. PId with an extra hexafluoroisopropylidene moiety is most sensitive to irradiation at high doses.
Title: Effects of Gamma Radiation on Various Polyimides
Description:
AbstractFour polyimides (PIa‐PId) containing 4,4′‐hexafluoroisopropylidene‐bisphthalic anhydride (6FDA) units in the backbone were prepared via one‐step synthesis.
The effects of different doses of gamma radiation from a cobalt‐60 source are studied.
The irradiated and the unirradiated polyimides are characterized by using tensile strength, infrared (IR), viscosity, differential scanning calorimeter (DSC), and gel permeation chromatography (GPC).
All polyimides show the increase of tensile strength and elongation at low doses (>350 Mrad).
The molecule weights decrease as the irradiation doses increase.
All samples showed a drastic degradation of the mechanical and thermal properties at doses above 1400 Mrad.
Samples irradiated at a dose of 2800 Mrad were completely brittle.
The major difference of the radiation effect of the polyimides depends largely on their structural differences.
PId with an extra hexafluoroisopropylidene moiety is most sensitive to irradiation at high doses.
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