A new aromatic tetracarboxylic dianhydride having a crank and twisted noncoplannar structure, 2,2ะ-bis(3,4-dicarboxyphenoxy)biphenyl dianhydride, was synthesized by the reaction of 4-nitrophthalonitrile with biphenyl-2,2ะ-diol, followed by hydrolysis and cyclodehydration. The biphenyl-2,2ะ-diyl-cont
Preparation and properties of soluble aromatic polyetherimides based on 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]hexafluoropropane dianhydride
โ Scribed by Dong-Ho Lee; Seung-Young Koo; Dae-Yong Kim; Heung-Jin Choi
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 190 KB
- Volume
- 76
- Category
- Article
- ISSN
- 0021-8995
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โฆ Synopsis
Aromatic polyetherimides were synthesized from a fluorine containing aromatic carboxylic acid dianhydride, 2,2-bis [4-(3,4-dicarboxyphenoxy)phenyl]hexafluoropropane dianhydride (6F-BABPA) and five typical aromatic diamines including 1,1-bis(4-aminophenyl)-1-phenyl-2,2,2-trifluoroethane (3F-DAM) by two-step procedures-amidation to polyamic acids (PAA), followed by thermal imidization of PAA. The chemical and physical properties of the newly prepared polyetherimides (PEI) were compared in terms of their chemical structures, inherent viscosities, mechanical, and thermal properties. All polyetherimides were well soluble in common organic solvents such as N-methyl-2-pyrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), pyridine, and methylene chloride. A PEI prepared from 6F-BABPA/3F-DAM was especially easily dissolved in NMP. The glass transition temperature (T g ) range of the obtained PEI was 209 -257ยฐC. The dielectric constants and refractive index were 2.8 -3.2 and 1.61-1.56, respectively. The polyetherimide, 6F-BABPA/BAPP, with a low fluorine content (11.4% fluorine content), has 0.99% water absorption, whereas the polyetherimide, 6F-BABPA/4-BDAP, having a high fluorine content (26.0% fluorine content) showed 0.35% of water absorption.
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