Modeling for morphology development during single-screw extrusion of LDPE/PS blend

A computer model for a single-screw plasticating extrusion SSEM (developed by Wilczynski [Teoria Wytlaczania Jednoslimakowego, Warsaw University of Technology Publication, Warsaw, 1990; Polym. Plast. Technol. Eng. 35 (1996) 449]) has been modified to model polyblend extrusion. The model has been applied for description of the nascent morphology of an immiscible binary polyblend of low-density polyethylene and polystyrene (LDPE/PS) compounded in the single-screw extruder. It was observed that the fibrillation/disintegration breakup mechanism prevails in the (conventional) single-screw extruder, and the filaments break when their diameter falls below the critical value (D < D-f) rather than the reduced capillary number decreases below four, k* < 4. (C) 2001 Elsevier Science B.V. All rights reserved.