constitutional heterogeneity

of polymers
https://doi.org/10.1351/goldbook.C01283
The variation in @C01282@ from molecule to molecule in polymers with molecules uniform with respect to elemental composition. An example is a polymer composed of linear and branched molecules; another example is a @S05955@ comprising two @I03291@ constitutional units.
Source:
Purple Book, 1st ed., p. 52 [Terms] [Book]