AUTHOR=Sanz Alejandro , Linares Amelia , García-Gutiérrez Mari Cruz , Nogales Aurora , Paszkiewicz Sandra , Zubkiewicz Agata , Szymczyk Anna , Ezquerra Tiberio A. 

TITLE=Relaxation Dynamics of Biomass-Derived Copolymers With Promising Gas-Barrier Properties

JOURNAL=Frontiers in Chemistry

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.921787

DOI=10.3389/fchem.2022.921787

ISSN=2296-2646

ABSTRACT=This article presents an experimental study on the relaxation dynamics of a series of random
 copolymers based on bio-friendly comonomers with interesting gas barrier properties. We
analyze the relaxation response in the glassy and ultraviscous regime of poly(trimethylene
furanoate/sebacate) random copolymers via dielectric spectroscopy. We report lower values of
dynamic fragility (a dimensionless index introduced in 1985 (Angell, 1985)) in comparison to
popular polyesters widely used in industry, such as poly(ethylene terephthalate), suggesting
that the amorphous phase of these furanoate-based polyesters adopt an efficient chain packing.
 This is consistent with their low permeability to gases. We also discuss on different equations
 (phenomenological and theory-based approaches) for fitting the temperature-evolution of the
alpha relaxation time.