Preparation and properties of a new aromatic polyamide with an ethoxycarbonyl pendant group: Poly(4,4′-diamino-2′-ethoxycarbonyl-benzanilide terephthalamide)
✍ Scribed by Seog Joo Kang; Sung Il Hong; Chong Rae Park
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 171 KB
- Volume
- 38
- Category
- Article
- ISSN
- 0887-624X
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✦ Synopsis
A new aromatic polyamide containing a pendant ethoxycarbonyl group was successfully synthesized from the reaction between 4,4Ј-diamino-2Ј-ethoxycarbonylbenzanilide and terephthaloyl chloride. The new polymer was soluble in organic solvents such as N-methyl-2-pyrrolidone and dimethylacetamide, and a tough and transparent film was cast from the polymer solution with viscosities ranging from 2.6 to 5.6 dL/g. When the polymer film was heat-treated at a temperature greater than 300 °C, a cyclization reaction occurred between the ethoxycarbonyl group and the adjacent amide bond to form a benzoxazinone unit in the polymer backbone. The thermal decomposition onset temperature of the cyclized film was about 523 °C, which was somewhat lower than that of poly(p-phenylene terephthalamide) (PPTA; 566 °C); however, the decomposition rate was slower than that of PPTA to yield a higher char residue. The dispersion temperature of the uncyclized poly(4,4Ј-diamino-2Ј-ethoxycarbonylbenzanilide terephthalamide) (PDEBTA) was about 340 °C, whereas that of the cyclized PDEBTA was not clear.