Influence of Cyclobutane Segments in Cycloaliphatic Decahydronaphthalene-containing Copolyesters
Polymers and High Performance Materials
Melt transesterification polycondensation enabled the incorporation of rigid, cycloaliphatic diols (2,2,4,4-tetramethylcyclobutane-1,3-diol) into decahydronaphthalene-containing copolyesters, which resulted in amorphous, optically clear materials. Glass transition temperatures approached 155 degrees C and followed predictable trends using the Fox equation for randomly sequenced copolymers. Dynamic mechanical analysis identified several low-temperature relaxations attributed to the complex motions of the decahydronaphthalate and cyclohexyl rings within the polymer backbone. Furthermore, incorporating cyclobutane rings suppressed the low-temperature local mobility, revealing a strong structural dependence on these relaxations. The rheological simplicity of these nonassociating chains permitted analysis over a large frequency window using time-temperature superposition. As a result, the characteristic relaxation times provided insight into chain dynamics and the propensity for chain entanglements. Finally, positron annihilation lifetime spectroscopy probed hole-free volume and reinforced the trends observed with oxygen permeability measurements.
High Performance Polymers
Dennis, J. M.,
Fazekas, N. A.,
Mondschein, R. J.,
Long, T. E.
(2017). Influence of Cyclobutane Segments in Cycloaliphatic Decahydronaphthalene-containing Copolyesters. High Performance Polymers, 29(6), 750-756.
Available at: https://aquila.usm.edu/fac_pubs/17665