The effect of new additives on the thermal conversion of a range of polyamic acids to polyimides at temperatures lower than 100Β°C was investigated using infrared spectroscopy. Additives such as m-hydroxybenzoic acid, p-hydroxyphenylacetic acid, and p-hydroxybenzenesulfonic acid were found to be high
Polyamic acids: Thermal and microwave imidization and film properties
β Scribed by V. S. Kishanprasad; P. H. Gedam
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 604 KB
- Volume
- 50
- Category
- Article
- ISSN
- 0021-8995
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β¦ Synopsis
Polyamic acids were synthesized from benzophenonetetracarboxylic &anhydride and diamines, viz., 4,4'-diaminodiphenyl methane and 4,4'-diaminodiphenyl ether. The course of imidization of the polyamic acids both by thermal and microwave treatments was tracked by infrared spectroscopy. The mechanical properties, namely the tensile strength and toughness of the films of polyimides with varying degree of imidization obtained by the two treatments were compared. The effect of degree of imidization of polyimide coatings on adhesion to copper substrate was also studied. Nearly 100% imidization was achieved by the thermal process, whereas the maximum imidization that could be achieved by the microwave process was about 50%. In thermal imidization, the adhesion values of the coatings slowly increased, attaining a maximum value at 80% imidization, after which there was a decrease in adhesion.
π SIMILAR VOLUMES
Solution properties such as viscosity, critical concentration, radius of gyration, and activation energy in aqueous solutions are described for [BPDA/PDA]polyamic acid (PAA) and their salts with various amines (PAS). Although PAA and their salts with BujN, HexxN, Oct3N, and pyridine, were insoluble
The polyether-ester polyamic acid imidization process in a solid state was studied by microwave radiation. The imidization content at different radiation times was calculated quantitatively by FTIR and was confirmed by the results of dynamic mechanical analysis (DMA). The microwave radiation imidiza