ma8b01210_si_001.pdf (407.17 kB)
Download fileThe Role of Chain-End Association Lifetime in Segmental and Chain Dynamics of Telechelic Polymers
journal contribution
posted on 19.10.2018, 17:03 authored by Kunyue Xing, Martin Tress, Peng-Fei Cao, Fei Fan, Shiwang Cheng, Tomonori Saito, Alexei P. SokolovBroadband dielectric
spectroscopy, differential scanning calorimetry,
and rheology were employed to study the impact of hydrogen (H)-bonding
end-groups on segmental and chain dynamics of telechelic polypropylene
glycol (PPG) and poly(dimethylsiloxane) (PDMS). Polymer chains with
three types of H-bonding end-groups possessing different interaction
strengths and a non-H-bonding end-group as reference were compared.
The glass transition temperature (Tg)
of H-bonding PPG systems with low molecular weight increases compared
to the reference, and the Tg difference
varies with chain-end interaction strength. In contrast, their shear
viscosities (for Tg-scaled temperature,
i.e., when the shift in Tg is accounted
for) are similar to that one of the reference. This is in strong contrast
to the behavior of telechelic PDMS with the same set of end-groups,
where the Tg increase of all H-bonding
systems is independent of H-bond strengths, while shear viscosity
increases significantly only for the strongest H-bonding end-groups.
These observations are explained by the difference in lifetime of
the end-group associations relative to segmental and chain relaxation
times.
History
Usage metrics
Read the peer-reviewed publication
Categories
Keywords
H-bonding PPG systemsPDMSshear viscosity increasesreferenceT gT g differencetelechelic polypropylene glycolglass transition temperatureChain-End Association LifetimeTelechelic Polymers Broadband dielectric spectroscopyT g increasechain relaxation timesH-bonding end-groupschain-end interaction strength