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The reactive extrusion of polyethylene/polypropylene blends
Author(s) -
Cheung P.,
Suwanda D.,
Balke S. T.
Publication year - 1990
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.760301710
Subject(s) - reactive extrusion , polypropylene , materials science , plastics extrusion , compatibilization , extrusion , polyethylene , differential scanning calorimetry , composite material , izod impact strength test , linear low density polyethylene , yield (engineering) , copolymer , scanning electron microscope , polymer blend , polymer , ultimate tensile strength , physics , thermodynamics
The objective of this work was to investigate the compatibilization of a blend of linear low density polyethylene with polypropylene by Injection of a free radical initiator during extrusion. The reactive extrusion process utilized a single screw extruder equipped with two static mixers. The initiator was injected into the extruder feedport and temperature programming used to cause most reaction to occur within the static mixers. Although elongation at yield was increased by 37 percent, impact strength and yield strength decreased by 17 and 54 percent, respectively. Scanning electron microscopy showed that the maximum size of the dispersed phase decreased from a maximum size of four microns to less than two microns upon addition of initiator. Size exclusion chromatography (SEC), temperature rising elution chromatography (TREF), and differential scanning calorimetry showed that the polypropylene in the blend was degrading while the polyethylene was increasing in molecular size. The combination of SEC and TREF was particularly useful in elucidating this result. No copolymer was discerned by any of the methods used.