Isothermal crystallization kinetics of poly(ethylene terephthalate) in blends with a liquid crystalline polyester (Vectra A)

✍ Scribed by Guo-Ping Chang-Chien; Morton M. Denn

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 445 KB
• Volume: 7
• Category: Article
• ISSN: 1042-7147
• DOI: 10.1002/(sici)1099-1581(199603)7:3<168::aid-pat531>3.0.co;2-h

✦ Synopsis

The isothermal crystallization kinetics of poly(ethy1ene terephthalate) (PET) in blends with a fully aromatic liquid crystalline copolyester (Vectra A) were studied with differential scanning calorimet y . PET c ystallization rates decrease with increasing Vectra fractions in the blend, and the percentage of PET that is crystalline also decreases with increasing Vectra. The equilibrium PET melting temperature for blends containing 40% or more Vectra is unambiguously below that of pure PET. Attenuated total reflectance Fourier-transform infrared spectroscopy measurements indicate that PETIVectra transesterification does not take place. The results are consistent with a scenario based on prior NMR data in which there is some interphase mixing between the liquid crystalline and flexible polymers and an increase in the fraction of gauche conformers in the PET.