6533b850fe1ef96bd12a81e7

RESEARCH PRODUCT

Junction Dynamics in Telechelic Hydrogen Bonded Polyisobutylene Networks

Ulf SeidelReimund StadlerMarcus MüllerBéla IvánHans Wolfgang SpiessVittoria BalsamoAlexander Dardin

subject

Length scalePolymers and PlasticsChemistryOrganic ChemistryActivation energyDielectricDynamic mechanical analysisAtmospheric temperature rangeDielectric spectroscopyInorganic ChemistryChemical physicsMaterials ChemistryStress relaxationRelaxation (physics)Physical chemistry

description

4-Urazoylbenzoic acid groups are attached to the chain ends of polyisobutylene. The cooperative assembling process of these polar groups is studied by DSC and dielectric and dynamic mechanical spectroscopy. The melting of the ordered clusters occurs in the temperature range 380-390 K. Distortions within the U4A clusters (Σ process) are monitored below the melting temperature T m with dielectric spectroscopy. On a larger length scale, these distortions also lead to stress relaxation which can be probed by dynamic mechanical measurements. Near T m , the relaxation ofU4A multiplets (α* relaxation) is detected with dielectric spectroscopy. In this temperature range, dynamic mechanical measurements show a transition from elastic behavior to viscous flow. The results are rationalized with molecular modeling calculations.

https://doi.org/10.1021/ma950984q