. (2011) 'Linking models of polymerization and dynamics to predict branched polymer structure and ow. ', Science., 333 (6051). pp. 1871-1874. Further information on publisher's website:http://dx.doi.org/10.1126/science.1207060 Publisher's copyright statement: This is the author's version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The denitive version was published in Science 333/6051, http://dx.doi.org/10.1126/science.1207060Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. One of the long-standing fundamental challenges to soft matter science is the quantitative connection between molecular topology and dynamics of branched entangled polymers. The motivation arises from both the universality of the physics (1) and the experimental and

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The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. SynopsisIn a recent short communication [Read, D. J. et al., Science 333, 1871(2011], we showed that a computational scheme can describe the nonlinear flow properties for a series of industrial lowdensity polyethylene (LDPE) resins starting from the molecular architecture. The molecular architecture itself is determined by fitting parameters of a reaction kinetics model to average structural information obtained from gel-permeation chromatography and light scattering. Flow responses of these molecules in transient uniaxial extension and shear are calculated by mapping the stretch and orientation dynamics of the segments within the molecules to effective pom-pom modes. In this paper, we provide the details of the computational scheme and present additional results on a LDPE and a high-density polyethylene resin to illustrate the dependence of segmental maximum stretch variables on the flow rate. V C 2014 The Society of Rheology.

An experimental correlation between the non‐linear behaviour of commercial polyethylene melts in LAOS flow, and the pressure fluctuations associated with melt flow instabilities developed in capillary rheometry are presented. Polyethylene melts with enhanced non‐linear behaviour under LAOS conditions present larger pressure fluctuations during capillary extrusion, and consequently, larger surface distortions on the extrudate. The combination of both methods can be a tool to predict the development of melt flow instabilities in the extrusion process of polyethylene melts, and can elucidate their correlation with material structural properties ($\overline M _{\rm w}$, MWD and topology).