Synthesis and properties of aromatic polyamides containing the cyclohexane structure

✍ Scribed by Sheng-Huei Hsiao; Chin-Ping Yang; Sheng-Wen Wang; Ming-Hung Chuang

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 196 KB
• Volume: 37
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19990915)37:18<3575::aid-pola4>3.0.co;2-w

✦ Synopsis

1,1-Bis[4-(4-carboxyphenoxy)phenyl]cyclohexane (III) and 1,1-bis[4-(4aminophenoxy)phenyl]cyclohexane (V) were prepared in two main steps starting from the aromatic nucleophilic substitution of p-fluorobenzonitrile and p-chloronitrobenzene, respectively, with 1,1-bis(4-hydroxyphenyl)cyclohexane in the presence of potassium carbonate in N,N-dimethylformamide (DMF). Using triphenyl phosphite and pyridine as condensing agents, two series of polyamides with cyclohexylidene cardo groups were directly polycondensated from dicarboxylic acid III with various aromatic diamines or from diamine V with various aromatic dicarboxylic acids in an N-methyl-2-pyrrolidone (NMP) solution containing dissolved calcium chloride. The polyamides exhibited inherent viscosities in the range of 0.45 to 1.78 dL/g. Almost all of the polymers were readily soluble in polar aprotic solvents such as NMP and N,N-dimethylacetamide (DMAc) and could afford transparent, flexible, and tough films by solution casting. The glass transition temperatures (T g ) of these aromatic polyamides were in the range of 180 -243°C by DSC, and the 10% weight loss temperatures in nitrogen and air were all above 450°C.