| 摘要 |
PURPOSE: A preparation method of polyimide foam by foaming polyimide precursor prepared by reaction of esterification reactant of aromatic carboxylic acid or its acid anhydride and alcohol compound with amine compound is provided which improves flexibility in keeping original characteristic of foam as it is. CONSTITUTION: In the preparing method of polyimide foam by foaming a polyimide precursor manufactured by reaction of esterification reactant of aromatic carboxylic acid or its acid anhydride and alcohol compound with amine compound, linear aliphatic diamine(H2N-(CH2)n-NH2, n = 4-12) and aromatic diamine as the amine compound are constituted in a mole ratio of 0.01-0.3:0.7-0.99. The polyimide precursor has a mean particle diameter of below 300 micro meters, an intrinsic viscosity of 0.01-0.2 dl/g. For an example, in pouring nitrogen into a 1L reactor at room temperature, 3,3',4,4'-benzophenontetracarboxylic acid dianhydride(BTDA:322.2g, 1 mole) is added in methyl alcohol(320 ml, 8 mole), esterified for 100 min by returning methyl alcohol, cooled to 50°C, blended with methylenedianiline(192.3g), hexamethylenediamine(3.5g) and isoquinoline(1.3g), added with Zonyl FSO 0.52g to give a liquid polyimide precursor, which is dried for at 60°C for 3 hr to remove methyl alcohol, and foamed in a microwave oven to give polyimide foam. The foam is useful for an adiabatic material, an absorber and a cushioning material of airplane, submarine, special ship etc.
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