Abstract

The present dielectric investigations of methyl-terminated poly(propylene glycol) (PPG) oligomers reveal that near the glass transition the normal modes and segmental relaxation merge in a single-process susceptibility spectrum, similar to previous observations on OH-terminated species. Moreover, the present shear-mechanical measurements demonstrate that the vanishing of chain modes can be monitored without recourse to dielectric investigations, which are able to access chain dynamics only for the relatively small fraction of type A polymers. As the normal and segmental modes merge, the viscosity displays a crossover from a polymer-like regime governed by the chain dynamics, to a simple-liquid regime governed by the structural relaxation.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.