Melt dynamics of supramolecular comb polymers: Viscoelastic and dielectric response

The structure and the dynamics of supramolecular comblike polymers in the melt state is studied by a combination of linear rheology, dielectric spectroscopy, and small angle neutron scattering. The system consists of blends of 1,2-polybutyleneoxide (PBO) entangled backbones, randomly functionalized with thymine (thy) and barely entangled PBO graft chains—modified with 2,4-diamino-1,3,5-triazine (DAT) end groups. These bioinspired groups associate into a transiently branched comb architecture through heterocomplementary interaction involving the two different hydrogen bonding groups thy and DAT. In the present manuscript, we focus on the comparison of the macroscopic dynamics of the associating blends and permanent comb analogs. The viscoelastic and dielectric response of covalent and reversible combs are found to be comparable. The viscoelastic response of mixtures of thy-functionalized entangled backbones and DAT-end-modified barely entangled chains show a relaxation mechanism, which is mostly attributed...