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NMR imaging of elastomeric polymers
Author(s) -
Koenig Jack L.
Publication year - 1994
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19940860122
Subject(s) - elastomer , materials science , natural rubber , polymer , dispersion (optics) , composite material , mixing (physics) , thermal expansion , polymer science , work (physics) , vulcanization , thermal , polymer chemistry , thermodynamics , optics , physics , quantum mechanics
We have used NMR imaging to determine the dispersion in crosslinking density in complex elastomers both along the chains as well as spatially. Our work has established that the ordinary industrial accelerator systems generate a broad distribution of crosslink densities in rubber articles due to the poor mixing of the solid accelerator/sulfur recipe in the raw rubber. This high inhomogeneity in elastomeric network has an adverse effect on the properties of the elastomer system. In particular, the variation in crosslink density leads to substantial differences in the coefficients of thermal expansion and high internal stresses in the rubber article.