Neutron Spin Echo Spectroscopy Viscoelasticity Rheology

Buch | Hardcover

VII, 248 Seiten

1997
Springer Berlin (Verlag)
978-3-540-62713-5 (ISBN)

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Viscoelasticandtransportpropertiesofpolymersintheliquid(solution,melt)or liquid-like (rubber) state determine their processing and application to a large extent and are of basic physical interest [1-3]. An understanding of these dynamic properties at a molecular level, therefore, is of great importance. However,thisunderstandingiscomplicatedbythefactsthatdi?erentmotional processes may occur on di?erent length scales and that the dynamics are governed by universal chain properties as well as by the special chemical structure of the monomer units [4,5]. The earliest and simplest approach in this direction starts from Langevin equations with solutions comprising a spectrum of relaxation modes [1-4]. Special features are the incorporation of entropic forces (Rouse model, [6]) which relax uctuations of reduced entropy, and of hydrodynamic interactions (Zimm model, [7]) which couple segmental motions via long-range back ow elds in polymer solutions, and the inclusion of topological constraints or entanglements (reptation or tube model, [8-10]) which are mutually imposed within a dense ensemble of chains. Another approach, neglecting the details of the chemical structure and concentratingontheuniversalelementsofchainrelaxation,isbasedondynamic scalingconsiderations[4,11].Inparticularinpolymersolutions,thisapproach o?ers an elegant tool to specify the general trends of polymer dynamics, although it su?ers from the lack of a molecular interpretation. A real test of these theoretical approaches requires microscopic methods, which simultaneously give direct access to the space and time evolution of the segmental di?usion. Here, quasi-elastic scattering methods play a crucial role sincetheyallowthemeasurementofthecorrespondingcorrelationfunctions.Inparticular,thehigh-resolutionneutronspinecho(NSE)spectroscopy[12-15]is very suitable for such investigations since this method covers an appropriate range in time (0.005)t/ns)40) and space (r/nm [15). Furthermore, the possibilityoflabellingbyhydrogen-deuteriumexchangeallowstheobservation of single-chain behavior even in the melt.

Neutron Spin Echo Investigations on the Segmental Dynamics of Polymers in Melts, Networks and Solutions.- Deformation and Viscoelastic Behavior of Polymer Gels in Electric Fields.- Rheology of Polymers Near Liquid-Solid Transitions.

Erscheint lt. Verlag	4.9.1997
Reihe/Serie	Advances in Polymer Science
Co-Autor	B. Ewen, M. Mours, D. Richter, T. Shiga, H.H. Winter
Zusatzinfo	VII, 248 p.
Verlagsort	Berlin
Sprache	englisch
Maße	155 x 235 mm
Gewicht	510 g
Themenwelt	Naturwissenschaften ► Chemie ► Organische Chemie
	Naturwissenschaften ► Physik / Astronomie ► Festkörperphysik
	Naturwissenschaften ► Physik / Astronomie ► Thermodynamik
	Technik ► Maschinenbau
Schlagworte	Makromoleküle • Polymer • Polymere • Rheologie • Viscoelastizität
ISBN-10	3-540-62713-8 / 3540627138
ISBN-13	978-3-540-62713-5 / 9783540627135
Zustand	Neuware