Copolymers sohd-state morphology

Abstract The optical achvities of poly-(R)-lactide, poly-(S)-lactide, poly(beta -hydroxybutyrate) and two beta -hydroxyvalerate copolymers were measured in soluhon, as solid powders in suspension, and where possible, as films. Poly-(plus)-3-methyl-I-pentene was also reinvestigated. In some cases the specific rotahon values of powder samples showed significant differences from the values of the solution measurements. The discrepancies of the data observed seem to reflect the local environment of the polymer chains in supermolecular assemblies and consequently the sohd state structure (morphology) of the polymers. The circular dichroism (CD) spectra of the polymers were also measured in solution and in the form of their films. For comparison, the CD spectra of the namrally occurring protein casein and of the synthetic polypeptide poly-(i-)-proline were also measured. (Author abstract) 2 I Refs. 

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