Article
Blending of Immiscible Polymers in a Mixing Zone of a Twin Screw Extruder- Effects of Compatibilization
Polymer Engineering and Science
(2000)
Abstract
The dependence of the morphology development of physical as well as of reactive
compatibilized polypropylene/polyamide 6 (PP /PA6) blends in a mixing zone of a
co-rotating twin screw extruder on blend composition and screw rotational speed
was investigated. A special process analytical set-up based on a co-rotating twin
screw extruder was used, which allowed melt sampling from different positions
along the operating extruder in time periods less than 10 seconds. It has been
shown that the disperse particle sizes in physical blends depend crucially on the
blend composition because of the increasing influence of coalescence with an increasing
concentration of the disperse phase. Furthermore, the morphology of
physical PP/PA6 blends depends strongly on their rheological properties. In contrast,
the influence of the screw rotational speed on the morphology is minor. The
resulting particle size in a mixing zone is achieved already after a short screw
length. The particle size of compatibilized blends is significantly smaller than in
physical blends because of the better conditions for drop break-up and the suppression
of coalescence effects. Due to this, compatibilization has a stronger influence
on the blend morphology than a variation of process or rheological conditions
with physical blends. Furthermore, the compatibilization leads to a concurrent
crystallization of the PA6 phase with the PP phase.
Keywords
- Blends,
- Immiscible Polymers,
- Mixing Zone,
- Twin Screw Extruder,
- Compatibilization
Disciplines
Publication Date
2000
Citation Information
William MacKnight, O. Franzheim, T. Rische and M. Stephan. "Blending of Immiscible Polymers in a Mixing Zone of a Twin Screw Extruder- Effects of Compatibilization" Polymer Engineering and Science Vol. 40 Iss. 5 (2000) p. 1143 - 1156 Available at: http://works.bepress.com/william_macknight/264/