Polymorphic structure and physical properties of the polyester/ether poly(ethylene-1,2-diphenoxyethane-p,p′ -dicarboxylate)

✍ Scribed by Shimizu, Jiro ;Okui, Norimasa ;Imai, Yoshitaka ;Nishide, Shingo ;Takaku, Akira

• Publisher: Wiley (John Wiley & Sons)
• Year: 1983
• Tongue: English
• Weight: 607 KB
• Volume: 21
• Category: Article
• ISSN: 0098-1273
• DOI: 10.1002/pol.1983.180210209

✦ Synopsis

Abstract

X‐ray diffraction studies of fibers of the polyester/ether poly(ethylene‐1,2‐diphenoxyethane‐p,p′ ‐dicarboxylate) (PEET) produced by high‐speed melt spinning show the existence of two polymorphic forms, designated α and β, in the solid state. The α form is obtained by annealing filaments melt spun at takeup speeds below 3000 m/min and is also found in samples crystallized from the melt and from dilute solutions. The α form has a monoclinic unit cell with dimensions a = 7.83, b = 10.33, c = 18.68 Å, and β = 83.1°. The equilibrium melting temperature and heat of fusion of the α form are 288.3°C and 19.1 cal/g, respectively. The β form predominates in highly oriented filaments obtained at takeup velocities above 6000 m/min. The unit cell is orthorhombic with dimensions a = 7.28, b = 5.65, and c = 18.64 Å. The β form does not transform to the α form on annealing.