@article{BrehmerFruebingHerkneretal.1995,
  author    = {Brehmer, Ludwig and Fr{\"u}bing, Peter and Herkner, G. and Kaminorz, Yvette},
  title     = {Pyroelektrische Untersuchungen an d{\"u}nnen Schichten von organischen Seitenkettenpolymeren},
  year      = {1995},
  language  = {de}
}
@article{FruebingBlischkeSalahKhaliletal.2001,
  author    = {Fr{\"u}bing, Peter and Blischke, D. and Salah Khalil, M. and Gerhard, Reimund},
  title     = {Complete relaxation map of polyethylene : filler-induced chemical modifications as dielectric probes},
  year      = {2001},
  language  = {en}
}
@article{FruebingBlischkeSalahKhaliletal.2001,
  author    = {Fr{\"u}bing, Peter and Blischke, D. and Salah Khalil, M. and Gerhard, Reimund},
  title     = {Dielectric relaxations in titanium-dioxide-filled polyethylene: Filler-induced chemical modifications of the polymer provide the dipolar response},
  isbn      = {0-7803-7053-8},
  year      = {2001},
  language  = {en}
}
@article{FruebingGrasnickHerkneretal.1995,
  author    = {Fr{\"u}bing, Peter and Grasnick, G. and Herkner, G. and Janietz, Dietmar and Brehmer, Ludwig},
  title     = {Pyroelektrische Untersuchungen an Polyvinylalkoholen mit Azobenzen / Alkoxy - Seitenketten},
  year      = {1995},
  language  = {de}
}
@article{FruebingKremmerGerhardetal.2006,
  author    = {Fr{\"u}bing, Peter and Kremmer, Alexander and Gerhard, Reimund and Spannoudaki, Anna and Pissis, Polycarpos},
  title     = {Relaxation processes at the glass transition in polyamide 11 : From rigidity to viscoelasticity},
  issn      = {0021-9606},
  doi       = {10.1063/1.2360266},
  year      = {2006},
  language  = {en}
}
@article{FruebingKremmerGerhardetal.2006,
  author    = {Fr{\"u}bing, Peter and Kremmer, Alexander and Gerhard, Reimund and Spanoudaki, Anna and Pissis, Polycarpos},
  title     = {Relaxation processes at the glass transition in polyamide 11: From rigidity to viscoelasticity},
  series = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr},
  volume    = {125},
  journal   = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr},
  number    = {12},
  publisher = {American Institute of Physics},
  address   = {Melville},
  issn      = {0021-9606},
  doi       = {10.1063/1.2360266},
  pages     = {8},
  year      = {2006},
  abstract  = {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.},
  language  = {en}
}
@article{FruebingKremmerNeumannetal.2004,
  author    = {Fr{\"u}bing, Peter and Kremmer, Alexander and Neumann, Werner and Gerhard, Reimund and Guy, I. L.},
  title     = {Dielectric relaxation in piezo-, pyro- and ferroelectric polyamide 11},
  year      = {2004},
  abstract  = {Ferroelectric polyamide 11 films were prepared by melt-quenching, cold-drawing and electrical poling. Their ferroelectricity was studied by means of dielectric-hysteresis measurements. A remnant polarisation of up to 35 mC/m(2) and a coercive field of 75 MV/m were obtained. The piezoelectric d(33) coefficient and the pyroelectric coefficient of the films are reduced by annealing just below the melting region, but remain at about 3 pC/N and 8 muC/(m(2)K), respectively, during further heat treatment. Differential scanning calorimetry (DSC), dielectric relaxation spectroscopy (DRS) and thermally stimulated depolarisation (TSD) were applied for investigating the conformational changes induced by melt-quenching, cold-drawing and annealing. The results indicate that the cold-drawn film mainly consists of a rigid amorphous phase which exhibits considerably lower conductivity, no glass transition and consequently no dielectric a relaxation. Instead, an a, relaxation is found, which is related to chain motions in regions of the rigid amorphous phase where the amide-group dipoles are not perfectly ordered. Annealing removes imperfectly ordered structures, but does not affect the ferroelectric polarisation. Therefore, it may be concluded that essentially the a, relaxation causes the thermally non-stable part of the piezo- and pyroelectricity in polyamide 11},
  language  = {en}
}
@article{FruebingKruegerGoeringetal.2002,
  author    = {Fr{\"u}bing, Peter and Kr{\"u}ger, Harald and Goering, H. and Gerhard, Reimund},
  title     = {Relaxation behaviour of thermoplastic polyurethanes with covalently attached nitroaniline dipoles},
  year      = {2002},
  language  = {en}
}
@article{FruebingWangWagener2012,
  author    = {Fr{\"u}bing, Peter and Wang, Feipeng and Wagener, Michael},
  title     = {Relaxation processes and structural transitions in stretched films of polyvinylidene fluoride and its copolymer with hexafluoropropylene},
  series = {Applied physics : A, Materials science \& processing},
  volume    = {107},
  journal   = {Applied physics : A, Materials science \& processing},
  number    = {3},
  publisher = {Springer},
  address   = {New York},
  issn      = {0947-8396},
  doi       = {10.1007/s00339-012-6838-1},
  pages     = {603 -- 611},
  year      = {2012},
  abstract  = {Relaxation processes and structural transitions in nonstretched and uniaxially stretched films of poly(vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP)) and its homopolymer polyvinylidene fluoride (PVDF) for comparison were investigated with the aim of understanding the electromechanical properties of this lower-modulus ferroelectric copolymer. The mechanical and the dielectric response at the glass transition ( relaxation) exhibit similar temperature dependence of the relaxation time, whereas mechanical and dielectric processes above the glass transition are not related. They represent a continuous softening process within the amorphous phase and the dielectric relaxation, respectively. The latter is attributed to conformational changes of VDF segments in lamellae of spherulites constituting the nonpolar crystalline phase. Furthermore, there is a contribution from melting of secondary crystallites formed in the amorphous phase during annealing or storage. Mechanically, this transition appears in nonstretched and stretched films as an accelerated decrease of the elastic modulus that terminates the rubber plateau. Dielectrically, this transition becomes visible as a frequency-independent loss peak only in stretched films, because stretching removes the relaxation, which superimposes the transition in nonstretched films. Melting of secondary crystallites is shown to appear in the homopolymer, too, though less pronounced because of more complete primary crystallisation. Stretching increases the modulus above the glass transition only slightly, and it does not significantly influence the softening process. On the other hand, stretching causes a spontaneous polarisation and introduces order within the amorphous phase, rendering it more polar. Melting of secondary crystallites provides an additional contribution to the polarisation. These findings may explain the relatively high electromechanical activity of P(VDF-HFP) but also its relatively low thermal stability. Moreover, they may be important for correct procedure and analysis of temperature-dependent dielectric measurements on partially crystalline polymers, in particular on those with less favourable sterical conditions for primary crystallisation.},
  language  = {en}
}
@article{FruebingWegenerGerhardetal.1999,
  author    = {Fr{\"u}bing, Peter and Wegener, Michael and Gerhard, Reimund and Buchsteiner, Alexandra and Neumann, Werner and Brehmer, Ludwig},
  title     = {Different molecular mechanisms for the dielectric hysteresis and pyroelectricity in a poly(vinyl alcohol) with azobenzene-alkoxy side chains},
  issn      = {0277-786X},
  year      = {1999},
  abstract  = {By means of pyroelectrical measurements and dielectric spectroscopy as well as structural information from differential scanning calorimetry, it is shown that, in a poly(vinyl alcohol) with azobenzene-alkoxy side chains, pyroelctricity and dielectric hysteresis which are usually related to each other have different origins. The pyroelectric effect is explained with reversible dipole-density changes upon thermal expansion, whereas the dielectric hysteresis is proposed to result from a charge-carrier polarisation.},
  language  = {en}
}