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Analysis of mixing during melt‐melt blending in twin screw extruders using reactive polymer tracers
Author(s) -
Shearer Gifford,
Tzoganakis Costas
Publication year - 1999
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.11552
Subject(s) - materials science , mixing (physics) , succinic anhydride , polypropylene , reactive extrusion , polymer , plastics extrusion , polyolefin , melt flow index , composite material , fourier transform infrared spectroscopy , static mixer , viscosity , molding (decorative) , chemical engineering , copolymer , physics , layer (electronics) , quantum mechanics , engineering
Mixing during melt‐melt blending of segregated polypropylene melt streams in a co‐rotating twin screw extruder was experimentally investigated. The mixing limited reaction between two polymer reactive tracers, which are terminally functionalized polyolefin oligomers, was used to determine the mixing performance of a kneading block section. The selected functional groups were succinic anhydride and a primary amine, and Fourier‐Transform Infrared Spectrometry (FT‐IR) was used to determine the anhydride conversion. In the absence of interfacial tension, the reaction conversion was directly related to the amount of interfacial area generated. Experiments were completed to study the effects of operating conditions, kneading block design, and polymer material properties. The screw speed effect was observed to be non‐linear because of competing contributions from shear rate, residence time, channel fill, and viscous heating. The mixing performance of kneading blocks backed by a reverse conveying element was observed to follow the trend of: forward > reverse > neutral. For each kneading block design, the mixing performance decreased with an increase in polymer viscosity.