Side-chain crystallization behavior of graft copolymers consisting of an amorphous main chain and crystalline side chains. II. Poly(n-hexyl methacrylate)-graft-poly(ethylene glycol)

✍ Scribed by Katsuhiro Inomata; Chieko Fukuda; Kuniyoshi Hori; Hideki Sugimoto; Eiji Nakanishi

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 409 KB
• Volume: 45
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/polb.21041

✦ Synopsis

Abstract

The phase behavior and crystallization of graft copolymers consisting of poly(n‐hexyl methacrylate) (PHMA) as an amorphous main chain and poly(ethylene glycol) (PEG) as crystallizable side chains (HMA__x__ with 15 ≤ x ≤ 73, where x represents the weight percentage of PEG) were investigated. Small‐angle X‐ray scattering profiles measured above the melting temperature of PEG suggested that a microdomain structure with segregated PHMA and PEG domains was formed in HMA40 and HMA46. This phase behavior was qualitatively described by a calculated phase diagram based on the mean‐field theory. Because of the segregation of PEG into microdomains, the crystallization temperature of the PEG side chains in HMA__x__ was higher than that in poly(methyl acrylate)‐graft‐poly(ethylene glycol) having a similar value of x, which was considered to be in a disordered state above the melting temperature. In HMA__x__ with x ≤ 40, PEG crystallization was strongly restricted, probably because the PEG microdomains were isolated in the PHMA matrix. As a result, the growth of PEG spherulite was not observed because the PEG crystallization occurred after vitrification of the PHMA segregated domains. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 129–137, 2007