Communication: This paper describes the investigation of butadiene rubber n
etworks varying in crosslink density by means of xenon (Xe-129) and deutero
n (H-2) NMR spectroscopy. Xe-129 NMR spectra give an evidence of structural
inhomogeneities inside the lower crosslinked network which were already ob
served in previous deuteron NMR studies under uniaxial deformation. The res
ults are discussed in comparison with theoretical models and simulations. I
t appears that experiment, theory and also simulation are: now coming toget
her to give a detailed picture of the behaviour of these rubbery materials.