Melt Miscibility in Diblock Copolymers Containing Polyethylene and Substituted Hydrogenated Polynorbornenes

• DOI: 10.1021/acs.macromol.7b01295
• Publication Date: 2017-07-25T10:33:30Z
• Authors: William D. Mulhearn; Richard A. Register
• Keywords: Miscibility; Hildebrand solubility parameter; Flory–Huggins solution theory

The thermodynamic interaction strengths between linear polyethylene (PE) and members of a family hydrogenated polynorbornenes prepared by ring-opening metathesis polymerization can be tuned across wide range via the choice substituent appended to polynorbornene backbone at 5-position. Isopropyl certain n-alkyl groups yield that are highly miscible with PE, capable producing symmetric diblock copolymers homogeneous melts molecular weights in excess 100 kg/mol. In contrast, phenyl-substituted quite immiscible exhibiting microphase separation melt as low 10 Interaction within this series polymers do not quantitatively obey regular mixing; entropic contributions mixing energy arising from mismatches free volume chain stiffness cannot account for observed deviations. Instead, interactions satisfactorily described an empirical rule form X = (Δγ)1.5, where is density γ pure-component quantity, operationally analogous solubility parameter, distinct value each polymer. These parameters obtained regression against entire set experimental pair energies.