## Abstract The Raman spectrum of polyβDLβalanine (PDLA) in the solid state is interpreted in terms of the disordered chain conformation, in analogy with the spectrum of mechanically deformed polyβLβalanine. The polymer is largely disordered with only a small Ξ±βhelical content in the solid state. W
Synthesis and characterization of di- and triblock copolymers of poly(ethylene oxide) and poly(dl-valine-co-dl-leucine)
β Scribed by Iwhan Cho; Jin-Baek Kim; Hyun-Jin Jung
- Publisher
- Elsevier Science
- Year
- 2003
- Tongue
- English
- Weight
- 389 KB
- Volume
- 44
- Category
- Article
- ISSN
- 0032-3861
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β¦ Synopsis
Di-and triblock copolymers of poly(ethylene oxide) (PEO) and poly(DL-valine-co-DL-leucine) were synthesized by ring-opening polymerization of N-carboxyanhydride (NCA)s of DL-valine and DL-leucine initiated by amine-terminated PEOs. The resulting block copolymers were characterized by 1 H NMR; FT-IR, DSC, and wide-angle X-ray diffraction (WAXD). Differential scanning calorimeter revealed that the melting temperature of triblock copolymer was lower than that of diblock copolymer and the study of WAXD patterns of triblock copolymer indicated that PEO segments are stretched during the copolymerization as shown in the formation of complex. The selfassembly behaviors of these di-and triblock copolymers in the aqueous solution showed various forms.
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