Relaxation processes at the glass transition in polyamide 11: From rigidity to viscoelasticity

Frubing, P; Kremmer, A; Gerhard-Multhaupt, R; Spanoudaki, A; Pissis, P

dc.contributor.author	Frubing, P	en
dc.contributor.author	Kremmer, A	en
dc.contributor.author	Gerhard-Multhaupt, R	en
dc.contributor.author	Spanoudaki, A	en
dc.contributor.author	Pissis, P	en
dc.date.accessioned	2014-03-01T01:25:04Z
dc.date.available	2014-03-01T01:25:04Z
dc.date.issued	2006	en
dc.identifier.issn	0021-9606	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/17526
dc.subject.classification	Physics, Atomic, Molecular & Chemical	en
dc.subject.other	Annealing	en
dc.subject.other	Crystallization	en
dc.subject.other	Dielectric relaxation	en
dc.subject.other	Mechanical properties	en
dc.subject.other	Quenching	en
dc.subject.other	Rigidity	en
dc.subject.other	Spectroscopic analysis	en
dc.subject.other	Amorphous phase	en
dc.subject.other	Cold drawing	en
dc.subject.other	Dielectric relaxation spectroscopy (DRS)	en
dc.subject.other	Molecular mobility	en
dc.subject.other	Polyamides	en
dc.title	Relaxation processes at the glass transition in polyamide 11: From rigidity to viscoelasticity	en
heal.type	journalArticle	en
heal.identifier.primary	10.1063/1.2360266	en
heal.identifier.secondary	http://dx.doi.org/10.1063/1.2360266	en
heal.identifier.secondary	214701	en
heal.language	English	en
heal.publicationDate	2006	en
heal.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. (c) 2006 American Institute of Physics.	en
heal.publisher	AMER INST PHYSICS	en
heal.journalName	Journal of Chemical Physics	en
dc.identifier.doi	10.1063/1.2360266	en
dc.identifier.isi	ISI:000242646200027	en
dc.identifier.volume	125	en
dc.identifier.issue	21	en