TY  - JOUR
A1  - Kremmer, Alexander
A1  - Ganser, J.
A1  - Pissis, Polycarpos
A1  - Gerhard, Reimund
T1  - Dielectric relaxation and resonance spectra of ferroelectric polyamide 11
Y1  - 2003
SN  - 0-7803-7560-2
ER  - 
TY  - JOUR
A1  - Frübing, Peter
A1  - Kremmer, Alexander
A1  - Gerhard, Reimund
A1  - Spanoudaki, Anna
A1  - Pissis, Polycarpos
T1  - Relaxation processes at the glass transition in polyamide 11: From rigidity to viscoelasticity
JF  - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr
N2  - Relaxation processes associated with the glass transition in nonferroelectric and ferroelectric polyamide (PA) 11 are investigated by means of differential scanning calorimetry, dynamic mechanical analysis, and dielectric relaxation spectroscopy (DRS) in order to obtain information about the molecular mobility within the amorphous phase. In particular, the effects of melt quenching, cold drawing, and annealing just below the melting region are studied with respect to potential possibilities and limitations for improving the piezoelectric and pyroelectric properties of PA 11. A relaxation map is obtained from DRS that shows especially the crossover region where the cooperative alpha relaxation and the local beta relaxation merge into a single high-temperature process. No fundamental difference between quenched, cold-drawn, and annealed films is found, though in the cold-drawn (ferroelectric) film the alpha relaxation is suppressed and slowed down, but it is at least partly recovered by subsequent annealing. It is concluded that there exists an amorphous phase in all structures, even in the cold-drawn film. The amorphous phase can be more rigid or more viscoelastic depending on preparation. Cold drawing not only leads to crystallization in a ferroelectric form but also to higher rigidity of the remaining amorphous phase. Annealing just below the melting region after cold drawing causes a stronger phase separation between the crystalline phase and a more viscoelastic amorphous phase.
Y1  - 2006
U6  - https://doi.org/10.1063/1.2360266
SN  - 0021-9606
VL  - 125
IS  - 12
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Frübing, Peter
A1  - Kremmer, Alexander
A1  - Gerhard, Reimund
A1  - Spannoudaki, Anna
A1  - Pissis, Polycarpos
T1  - Relaxation processes at the glass transition in polyamide 11 : From rigidity to viscoelasticity
Y1  - 2006
UR  - http://jcp.aip.org/
U6  - https://doi.org/10.1063/1.2360266
SN  - 0021-9606
ER  -