Synthesis and properties of polyimides derived from 1,4-bis(4-aminophenoxy)2,5-di-tert-butylbenzene

✍ Scribed by Der-Jang Liaw; Been-Yang Liaw

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 174 KB
• Volume: 35
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(199706)35:8<1527::aid-pola21>3.0.co;2-8

✦ Synopsis

Novel aromatic polyimides containing symmetric, bulky di-tert-butyl substituents unit were synthesized from 1,4-bis(4-aminophenoxy)2,5-di-tert-butylbenzene (BADTB) and various aromatic tetracarboxylic dianhydrides by the conventional twostage procedure that included ring-opening polyaddition in a polar solvent such as N,Ndimethylacetamide to give poly(amic acid)s, followed by cyclodehydration to polyimides. The diamine was prepared through the nucleophilic displacement of 2,5-di-tertbutylhydroquinone with p-chloronitrobenzene in the presence of K 2 CO 3 , followed by catalytic reduction. Depending on the dianhydrides used, the poly(amic acid)s obtained had inherent viscosities of 0.83-1.88 dL g 01 . Most of the polyimides formed transparent, flexible, and tough films. Tensile strength and elongation at break of the BADTBbased polyimide films ranged from 68-93 MPa and 7-11%, respectively. The polyimide derived from 4,4 -hexafluoro-isopropylidenebisphathalic anhydride had better solubility than the other polyimides. These polyimides had glass transition temperatures between 242-298ЊC and 10% mass loss temperatures were recorded in the range of 481-520ЊC in nitrogen.