Abstract
The effects of molecular characteristics on the rheology and melt fracture of several linear and branched low-density polyethylene (LLDPE and LDPE) resins in capillary extrusion were studied as functions of molecular weight, polydispersity and the level of long chain branching (LCB). The level of LCB in the resins was found qualitatively by using several rheological methods which in general agree. These are based on the zero-shear viscosity versus molecular weight relationship, the energy of activation, the linear viscoelastic properties and the characteristic shapes of the flow curves. A previously proposed criterion (critical shear stress versus plateau modulus) for the onset of sharkskin melt fracture (Allal et al., J. Non-Newtonian Fluid Mech., 134 (2006) 127–135) was tested and found to give reasonable predictions for the sharkskin instability of the polyethylenes considered in this work.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
