Melt polymerization of copoly(ethylene terephthalate–imide)s and thermal properties

✍ Scribed by Lee Soon Park; Jeong Hoe Do; Dong Chan Lee

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 462 KB
• Volume: 60
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19960620)60:12<2059::aid-app3>3.0.co;2-l

✦ Synopsis

SYNOPSIS

Copoly(ethy1ene terephthalate-imide)s (PETI) were prepared by melt polycondensation of bis(2-hydroxyethy1)terephthalate (BHET) and imide containing oligomer, i.e., 4,4'-bis[(4carbo-2-hydroxyethoxy)phthalimido]diphenylmethane (BHEI). The apparent rate of polycondensation reaction was faster than that of homo poly(ethy1ene terephthalate) (PET) due to the presence of imide units. The PETI copolymers with up to 10 mol % of BHEI unit in the copolymer showed about the same molecular weight and carboxyl end group content as homo PET prepared under similar reaction conditions. The increase in Tg of copolymer was more dependent on molar substitution of BHEI than on substitution of BHEN, reaching 91°C with 8 mol % BHEI units in the copolymer from TB = 78.9"C of homo PET. In the case of PETN copolymer, 32 mol % of bis(2-hydroxyethy1)naphthalate (BHEN) units gave Tg of 90°C. The maximum decomposition temperature of PETI copolymer was about the same as that of homo PET by TGA analysis. The char yield at 800°C was higher than that of homo PET.