Synthesis and characterization of novel poly(amide-imide)s containing hexafluoroisopropylidene linkage

✍ Scribed by Der-Jang Liaw; Been-Yang Liaw; Jeng-Ming Tseng

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 142 KB
• Volume: 37
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19990715)37:14<2629::aid-pola37>3.0.co;2-3

✦ Synopsis

A series of novel soluble poly(amide-imide)s were prepared from the diimide-dicarboxylic acid, 2,2-bis[N-(4-carboxyphenyl)-phthalimidyl]hexafluoropropane, with various diamines by the direct polycondensation in N-methyl-2-pyrrolidinone containing CaCl 2 using triphenyl phosphite and pyridine as condensing agents. All the polymers were obtained in quantitative yields with inherent viscosities of 0.78 -1.63 dL g Ϫ1 . The polymers were amorphous and readily soluble in aprotic polar solvents such as N-methyl-2-pyrrolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide as well as in less polar solvents such as pyridine and ␥-butyrolactone, and also in tetrahydrofuran. The polymer films had tensile strength of 84 -129 MPa, an elongation at break range of 6 -22%, and a tensile modulus range of 2.0 -2.7 GPa. The glass transition temperatures of the polymers were determined by DSC method and they were in the range of 240 -282°C. These polymers were fairly stable up to a temperature around or above 400°C, and lose 10% weight in the range of 450 -514°C and 440 -506°C in nitrogen and air, respectively.