Amorphous-Crystalline PSnPEOn Heteroarm Star Copolymers: Crystallinity and Crystallization Kinetics

✍ Scribed by Eleni Koutsopoulou; Constantinos Tsitsilianis

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 276 KB
• Volume: 205
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.200400120

✦ Synopsis

Abstract

Summary: The crystallization behavior and kinetics of poly(ethylene oxide) in polystyrene/poly(ethylene oxide) heteroarm star copolymers were studied by differential scanning calorimetry and optical microscopy. A comparison between star and linear amorphous‐crystalline block copolymers showed that the macromolecular architecture is an important factor affecting crystallinity. The following points were observed: the equilibrium melting point is higher in the star copolymers, the crystallinity reduces as the number of arms increases, leading to smaller and ill‐defined spherulites, and crystallization proceeds faster in linear copolymers at low supercooling.

Half crystallization times, t~1/2~, calculated from the Avrami analysis of the latent heats, obtained during the isothermal crystallization experiments as a function of supercooling, Δ__T__, for all copolymers.

magnified imageHalf crystallization times, t~1/2~, calculated from the Avrami analysis of the latent heats, obtained during the isothermal crystallization experiments as a function of supercooling, Δ__T__, for all copolymers.