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Probing molecular mobility during crosslinking process of commercial resins by NMR multiexponential relaxation data analysis
Author(s) -
de L. Campello Sérgio,
de Souza Ricardo E.,
de Azevedo Walter M.
Publication year - 2011
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.33827
Subject(s) - relaxation (psychology) , materials science , magnetization , population , polyester , monomer , polymer , decomposition , polymer chemistry , thermodynamics , chemistry , chemical engineering , organic chemistry , composite material , physics , psychology , social psychology , demography , quantum mechanics , sociology , magnetic field , engineering
In this study, we present the experimental results for the crosslinking process of a commercial polyester resin based on measurements of the spin lattice relaxation time T 1 of protons, as function of the crosslinking time evolution. Multiexponential decomposition of the evolution of magnetization measured in inversion‐recovery experiments is performed. The population of “rigid” and “mobile” nuclear spin sites was estimated as function of time evolution. In analogy to the usual monomer conversion u , site conversion from “mobile” to “rigid” sites u M were also estimated as a function of time evolution and initial concentrations of the reagents. The multiexponential decomposition approach of T 1 relaxation data allows one to follow crosslinking processes. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011