A. Lungu et Dc. Neckers, SOLUTION AND SOLID C-13 NMR-STUDIES OF MULTIFUNCTIONAL POLYOLACRYLATENETWORKS, JCT, Journal of coatings technology, 67(850), 1995, pp. 29-35
Citations number
13
Categorie Soggetti
Chemistry Applied","Materials Science, Coatings & Films
Several C-13 NMR techniques are introduced to address the problem of s
tructure determination of photopolymerized polyolacrylates, and to stu
dy both the liquid and solid states of acrylic monomers and oligomers,
as well as the network structure formed upon their photopolymerizatio
n. By measuring the relative integration of specific peaks in the carb
on spectra as a function of the time of irradiation and laser power, t
he relative reactivity of monomers/oligomers used in the early stages
of polymerization is determined. Changes in crosslink density and in t
he mobility of the polymeric chains can be followed throughout the pho
topolymerization process by monitoring proton T-1 rho relaxation times
. The degree of crosslinking is correlated to the relaxation times and
it increases with an increasing power of the irradiating laser even u
nder conditions where the degree of conversion, as measured by quantit
ative infrared absorption of the 810 cm(-1) band of the acrylate is al
most unchanged.