Investigation of ageing processes and crosslink density inhomogeneities by parameter selective NMR microscopy

Author

Kuhn, W.

Author_Institution

Fraunhofer Inst. for Biomed. Eng., St. Ingbert, Germany

fYear

1994

fDate

2/9/1994 12:00:00 AM

Firstpage

42522

Abstract

Summary form only given: The aim of the author´s work is to demonstrate the potential of NMR imaging for spatially resolved determination of material properties. T₁,T₂,T_1p-imaging experiments were performed on aged technical rubber samples and of such with different crosslink densities as well. The NMR data were analysed using the BPP and Anderson-Weiss theory (BPP-AW) and the theory of Limited Translational Defect Diffusion (LTDD). The results reveal the different frequency components of the molecular motion, the nonaveraged dipolar interaction q*M₂ and the crosslink density. From LTDD theory the defect size of chain entanglements, diffusion distance and defect diffusion coefficients could be derived. Histogram analysis of all parameters derived from the data evaluation shows clearly crosslink density inhomogeneities

Keywords

ageing; environmental degradation; nondestructive testing; nuclear magnetic resonance imaging; nuclear spin-lattice relaxation; polymer structure; rubber; spin-spin relaxation; Anderson-Weiss theory; Limited Translational Defect Diffusion; NMR imaging; aged technical rubber; ageing processes; chain entanglements; crosslink density inhomogeneities; defect size; diffusion distance; frequency components; molecular motion; nonaveraged dipolar interaction; oxidative ageing; parameter selective NMR microscopy; proton relaxation; spatially resolved determination; spin-lattice relaxation; spin-spin relaxation;

fLanguage

English

Publisher

iet

Conference_Titel

NMR/MRI used in NDT, IEE Colloquium on

Conference_Location

London

Type

conf

Filename

283710