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Licensed Unlicensed Requires Authentication Published by De Gruyter June 3, 2013

Blend Morphology of Linear Low Density Polyethylene and Polystyrene in a Non-Intermeshing Twin Screw Extruder

L.-Y. Yang, T. G. Smith and D. Bigio

Abstract

Morphology development was investigated during blending of linear low density polyethylene (LLDPE) and polystyrene (PS) (the minor phase) in a tangential counter-rotating twin screw extruder, with and without the use of 5 wt.-% Kraton styrene-ethylene/butylene-styrene (SEBS) triblock copolymers as compatibilizing agents. Dispersive mixing in the Non-Intermeshing Twin Screw Extruder (NITSE) is improved with an increase of percent drag flow up to 50 %; the screws configuration includes reverse flight elements and/or cylinders. Experiments have indicated that the combined effect of the reverse flight elements and cylinders increases the reduction rate of droplets due to a longer time in the feed screw where the most significant changes of phase morphology occur. Screw stagger has been shown to have a minor effect on the phase scale of the final dispersion. The more significant reduction of the phase scale is achieved by increasing screw speed under constant flow conditions.


* Mail address: Dr. David Bigio, Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA

Received: 1995-6-29
Accepted: 1996-9-20
Published Online: 2013-06-03
Published in Print: 1997-03-01

© 1997, Carl Hanser Verlag, Munich