Block copolypeptides. 2. Viscoelastic properties.

The solid state structure of block copolypeptides of gamma-benzyl L-glutamate (G) and L-leucine (L) case from preferential solvents for G has been investigated by dynamic mechanical and wide angle x-ray diffraction techniques. The WAXD patterns show overlapping reflections characteristic of the individual homopolymers. Further evidence for a phase separated morphology is provided by the viscoelastic behavior. Representation of the dynamic elastic modulus in terms of the equivalent mechanical model suggests that phase separation of GLG-type polymers occurs with G as the matrix phase. In the reverse case, LGL-type polymers, it appears that some phase inversion has taken place.