Elastomeric Polymers. 1. Application of Proton NMR Imaging to the

Proton NMR imaging techniques were used to characterize a silicone rubber, intended mainly
for biomedical applications, modified by an “in situ” polymerization. The study was aimed at the
investigation of the effect of the polymerization on the silicone properties and of the dispersion of the
guest polymer inside the host matrix. Before the onset of the reaction, the silicone, swollen either in
water or in toluene, was characterized. Any source of inohomogeneities such as air bubbles or defects
was localized and measured, and the geometry was recognized. By comparing the signal intensity from
images collected before, during and after the polymerization reaction as well as the T1 and T2 relaxation
time values, the guest polymer was found almost homogeneously dispersed in the host matrix, without
preferential locations and/or agglomerates. The silicone network did not appear significantly altered by
the presence of the guest polymer. The occurrence of the “in situ” polymerization reaction was proved by
infrared spectroscopy.