TY - JOUR
T1 - Dielectric and thermal characterization of low density ethylene/10-undecen-1-ol copolymers prepared with nickel catalysts
AU - Andrade, Maria Madalena Alves Campos de Sousa Dionísio
PY - 2007/1/1
Y1 - 2007/1/1
N2 - Ethylene and 10-undecen-1-ol copolymers, prepared using a nickel complex as catalyst, were studied using differential scanning calorimetry (DSC), X-ray diffraction, and dielectric relaxation spectroscopy. The behavior exhibited by copolymers containing incorporated 10-undecen-1-ol amounts within 0.5 and 4.6 mol % was compared with neat polyethylene. DSC revealed that a new crystalline region with lower thickness lamellae emerges in copolymers due to the side-chains crystallization. Nevertheless, the global crystallization degree decreases due to the loss of crystallinity that occurs in a greater extent in PE-like regions. Dielectric relaxation spectroscopy detected two processes, a low activation energy process below -20 degrees C related with localized mobility increasing in intensity and deviating to higher temperatures with the increase in 10-undecen-1-ol amount, and a high activation energy process ascribed to the glass transition, located at higher temperatures for the different copolymers relatively to neat polyethylene. (c) 2007 Wiley Periodicals, Inc.
AB - Ethylene and 10-undecen-1-ol copolymers, prepared using a nickel complex as catalyst, were studied using differential scanning calorimetry (DSC), X-ray diffraction, and dielectric relaxation spectroscopy. The behavior exhibited by copolymers containing incorporated 10-undecen-1-ol amounts within 0.5 and 4.6 mol % was compared with neat polyethylene. DSC revealed that a new crystalline region with lower thickness lamellae emerges in copolymers due to the side-chains crystallization. Nevertheless, the global crystallization degree decreases due to the loss of crystallinity that occurs in a greater extent in PE-like regions. Dielectric relaxation spectroscopy detected two processes, a low activation energy process below -20 degrees C related with localized mobility increasing in intensity and deviating to higher temperatures with the increase in 10-undecen-1-ol amount, and a high activation energy process ascribed to the glass transition, located at higher temperatures for the different copolymers relatively to neat polyethylene. (c) 2007 Wiley Periodicals, Inc.
U2 - 10.1002/polb.21275
DO - 10.1002/polb.21275
M3 - Article
VL - 45
SP - 2802
EP - 2812
JO - Journal Of Polymer Science Part B-Polymer Physics
JF - Journal Of Polymer Science Part B-Polymer Physics
SN - 0887-6266
IS - 19
ER -