Susceptibility effect of carbon black filler on the deuterium NMR line shape from poly(butadiene) networks

Deuterium NMR line shapes of carbon black (N220) filled cis-1,4-poly(butadi ene) networks have been examined. The effect of the susceptibility of the f iller on the NMR line shape has been considered. The theory proposed by Bre reton and Ries for deuterium NMR line splitting in spectra of polymer netwo rks was used to fit the experimental data. It was found that the polymer se gments near the surface of a filler particle experience a different local m agnetic field from the remaining segments, due to the susceptibility of the carbon black. This effect gives rise to an asymmetry in the NMR spectrum, which until now has not been explained. Additionally, this analysis determi nes the fraction of polymer units affected by the local field of the filler particles and provides information about the effect of the macroscopic def ormation on these attached chains.