Characterisation of crosslinked elastomeric materials by H-1 NMR relaxation time distributions

One of the most critical structural parameters in elastomeric materials is the density of cross-linking between the polymeric chains. This chemical fe ature greatly affects chain motions and is determinant in controlling mecha nical properties of the final product. NMR techniques are widely and effici ently applied to investigation of such materials. In this study we have mea sured both transverse and longitudinal H-1 relaxation times of a series of polybutadiene rubber samples with increasing crosslink density induced by c hemical treatment. This approach allowed the observation of T-1 and T-2 dec rease with the increase of crosslink density in the samples examined. The d ata obtained have been analyzed and compared to theoretical models. (C) 200 1 Elsevier Science Inc. All rights reserved.