It is well known that deuteron NMR is a very sensitive tool for the investigation of order and orientation. H-2 NMR measurements of partially deuterated poly(butadiene) elastomers with systematically varied elastic properties are presented. H-2 NMR spectroscopy is applied to investigate the behaviour under uniaxially mechanical deformation. The segment order parameter S was found to be proportional to (lambda(2) -lambda(-1)), but to be different for intercrosslinked chains and dangling ends. The line splitting for both components is indirectly proportional to the mean molar mass between crosslinks M-C. It is shown that the line splitting obtained from maxima position gives only information about more mobile parts of the network. The results are compared to H-2 NMR transverse magnetization data based on the predictions of a model describing elastomer deuterium transverse magnetization data as a linear superposition of contributions from elastic chains and free dangling chain ends. The structural parameters are compared with results from mechanical and swelling measurements. The influence of microstructure, precursor chain length and their molar mass distribution as well as of the crosslink density on the transverse relaxation and the deformation behaviour were studied. (C) 2000 Elsevier Science Ltd. All rights reserved.