isomorphic polymer blend

Polymer blend of two or more different semi-crystalline polymers that are miscible in the crystalline state as well as in the molten state.
Notes:
  1. Such a blend exhibits a single, composition-dependent glass-transition temperature, T g, and a single, composition-dependent melting point, T m.
  2. This behaviour is extremely rare; very few cases are known.
Source:
PAC, 2004, 76, 1985 (Definition of terms related to polymer blends, composites, and multiphase polymeric materials (IUPAC Recommendations 2004)) on page 1988