TY - JOUR
T1 - Changes of the Molecular Mobility of Poly(ε-caprolactone) upon Drawing, Studied by Dielectric Relaxation Spectroscopy
AU - Yang, Xiao Yan
AU - Liu, Shao Shuai
AU - Korobko, Alexander V.
AU - Picken, Stephen J.
AU - Besseling, Nicolaas A.M.
PY - 2018/5/1
Y1 - 2018/5/1
N2 - Dielectric relaxation spectroscopy (DRS) of poly(ε-caprolactone) with different draw ratios showed that the mobility of polymer chains in the amorphous part decreases as the draw ratio increases. The activation energy of the α process, which corresponds to the dynamic glass transition, increases upon drawing. The enlarged gap between the activation energies of the α process and the β process results in a change of continuity at the crossover between the high temperature a process and the α and β processes. At low drawing ratios the a process connects with the β process, while at the highest drawing ratio in our measurements, the a process is continuous with the α process. This is consistent with X-ray diffraction results that indicate that upon drawing the polymer chains in the amorphous part align and densify upon drawing. As the draw ratio increases, the α relaxation broadens and decreases its intensity, indicating an increasing heterogeneity. We observed slope changes in the α traces, when the temperature decreases below that at which τα ≈ 1 s. This may indicate the glass transition from the ‘rubbery’ state to the non-equilibrium glassy state.
AB - Dielectric relaxation spectroscopy (DRS) of poly(ε-caprolactone) with different draw ratios showed that the mobility of polymer chains in the amorphous part decreases as the draw ratio increases. The activation energy of the α process, which corresponds to the dynamic glass transition, increases upon drawing. The enlarged gap between the activation energies of the α process and the β process results in a change of continuity at the crossover between the high temperature a process and the α and β processes. At low drawing ratios the a process connects with the β process, while at the highest drawing ratio in our measurements, the a process is continuous with the α process. This is consistent with X-ray diffraction results that indicate that upon drawing the polymer chains in the amorphous part align and densify upon drawing. As the draw ratio increases, the α relaxation broadens and decreases its intensity, indicating an increasing heterogeneity. We observed slope changes in the α traces, when the temperature decreases below that at which τα ≈ 1 s. This may indicate the glass transition from the ‘rubbery’ state to the non-equilibrium glassy state.
KW - Dielectric relaxation spectroscopy
KW - Molecular mobility
KW - Semicrystalline polymer
UR - http://www.scopus.com/inward/record.url?scp=85040582505&partnerID=8YFLogxK
U2 - 10.1007/s10118-018-2030-1
DO - 10.1007/s10118-018-2030-1
M3 - Article
AN - SCOPUS:85040582505
SN - 0256-7679
VL - 36
SP - 665
EP - 674
JO - Chinese Journal of Polymer Science (English Edition)
JF - Chinese Journal of Polymer Science (English Edition)
IS - 5
ER -