Synthesis and properties of poly(alkylene p,p′-bibenzoate-co-adipate)s

✍ Scribed by Da-Kong Lee; Hong-Bing Tsai

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 161 KB
• Volume: 65
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19970801)65:5<893::aid-app6>3.0.co;2-i

✦ Synopsis

Various poly(alkylene p,p-bibenzoate-co-adipate)s were prepared by melt polycondensation of dimethyl-p,p-bibenzoate, adipic acid, and an alkylene glycol. The copolyesters were characterized by inherent viscosity, FTIR, proton NMR, DSC, polarized microscopy, and X-ray diffraction. The polymer composition and sequence distribution of the copolyesters can be seen from NMR spectra. The copolyesters exhibit a degree of randomness of about 1, indicating that they are random copolymers. From the DSC data, the glass transition temperature ( T g ) and melting point ( T m ) of the copolyesters can be detected. When the content of the flexible adipate unit increases, the T g of copolyesters decreases significantly. The type of alkylene glycol used also affects the T g to some extent. The copolymerization effect decreases crystallinity and the T m of the copolyesters. The DSC, polarized microscopy, and X-ray diffraction data show that some copolyesters derived from 1,6-hexanediol exhibit a monotropic smectic phase. As the molar fraction of adipate unit in diacid units, x, is more than 0.4, the liquid crystallinity is completely destroyed.