Preparation and characterization of 3,3′,4,4′-benzophenone tetracarboxylic dianhydride-pyromellitic diahydride alternating polyimides

✍ Scribed by Yu Yang; Xujie Yang; Zhengliang Zhi; Lude Lu; Xin Wang

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 183 KB
• Volume: 64
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19970523)64:8<1585::aid-app15>3.0.co;2-x

✦ Synopsis

Four kinds of 3,3 ,4,4-benzophenone tetracarboxylic dianhydride (BTDA) -pyromelliitic dianhydride (PMDA) alternating polyimide (BTDA-PMDA API) were obtained by reacting 1 mol BTDA with 2 mol diamines to form BTDA chainextended diamines (BTDA CED), followed by the addition of 1 mol PMDA to yield the BTDA-PMDA alternating polyamic acids (BTDA-PMDA APA), and finally by imidizing them thermally. BTDA CED were characterized by elemental analysis, infrared (IR), and 1 H-NMR spectroscopy. The structures of BTDA-PMDA APA and BTDA-PMDA API were investigated by IR and 1 H-NMR spectroscopy, and their thermal properties and interfacial tension were also studied. Furthermore, the characteristic properties of BTDA-PMDA API were compared with their corresponding homopolyimides from BTDA (BTDA HPI) and from PMDA (PMDA HPI). It was found that the alternating condensation polymerization is an effective method to modify polyimides interfacial tension with a small influence on the thermal stability.