Synthesis and characterization of new polyamides containing adamantyl and diamantyl moieties in the main chain

✍ Scribed by Yaw-Terng Chern; Hann-Chyan Shiue; Shen C. Kao

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 195 KB
• Volume: 36
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19980415)36:5<785::aid-pola11>3.0.co;2-c

✦ Synopsis

This work synthesized a series of new polyamides by direct polycondensation of 1,3-bis[4-(4-carboxyphenoxy)phenyl]adamantane ( I) with various diamines. The diacid I was synthesized from 1,3-bis(4-hydroxyphenyl)adamantane in two steps. Polyamides III were soluble in N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), and pyridine. The polyamides had medium inherent viscosities of 0.30-0.55 dL/g and number-average molecular weights ( M n ) of 22,000-36,000. The polyamides III a and III b had tensile strengths of 59.8 and 77.5 MPa, elongation to breakage values of 5.8 and 7.6%, and initial moduli of 1.9 and 1.8 GPa, respectively. Their glass transition temperatures were found to be 219-295ЊC by means of differential scanning calorimetry (DSC). Dynamic mechanical analysis (DMA) reveals that the incorporation of rigid and bulky diamantane into polyamides III a and III b leads to high glass transition temperatures ( T g s), at 299 and 286ЊC, respectively. The decomposition temperatures of polyamides III at a 5% weight loss ranged from 388 to 416ЊC in air and from 408 to 435ЊC in N 2 atmosphere.