| Abstract
| - We present scattering data from a melt of H-shaped polybutadiene polymers, in which thecentral crossbar of the polymers is wholly labeled with deuterium. The melt was uniaxially stretched bya factor of 2, and using careful temperature control of the sample, the neutron scattering pattern wasmeasured after several different times of relaxation. The scattering data are compared against thepredictions of a new theory, based upon the tube model but which includes the additional effect of elasticinhomogeneities in the entanglement network. We find that with this new theory one can obtain a goodrepresentation of the data, using parameters that are consistent with relaxation times obtained from atube model description of the linear rheological data. The most important aspect of these data is anincreasing anisotropy of the correlation hole peak, and this appears to be directly related to the elasticinhomogeneities. One further aspect of the comparison to theory is that the best fits are obtained usinga Warner−Edwards tube diameter that deforms in a manner consistent with recent predictions for polymernetworks.
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