A hierarchical multi-mode MSF model for long-chain branched polymer melts part II: multiaxial extensional flows

In part I, a novel hierarchical multi-mode molecular stress function (HMMSF) model for long-chain branched (LCB) polymer melts has been proposed, which implements the basic ideas of (i) the pom-pom model, (ii) hierarchal relaxation, (iii) dynamic dilution, and (iv) interchain pressure. Here, the capability of this approach is demonstrated in modelling the extensional viscosity data of a broadly distributed long-chain branched polymer melt in uniaxial, equibiaxial, and planar extensional deformations with only a single non-linear parameter, the dilution modulus, which quantifies the fraction of dynamically diluted chain segments.