Unified mathematical model for linear viscoelastic predictions of linear and branched polymers

Application of the slip-link model to entangled star-branched polymers is considered. Relaxation of each arm by primitive-path length fluctuations occurs, as well as destruction and creation of entanglements by 'constraint dynamics'. Rouse dynamics to mimic constraint release is completely avoided. In addition, the branch point position can fluctuate and, in contrast to tube models, even pass through slip-links without stretching; all dynamics are determined by the chain free energy and Brownian forces. All adjustable parameters are determined from linear chain LVE comparisons. The proposed model is compared with the tube model, which contains certain limitations in premetive path relaxation that not found in the slip-link model. The proposed formulation can be applied to more complicated branches and to cross-linked networks as well.