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Processing of polyolefin blends
Author(s) -
Ho WuJing,
Salovey R.
Publication year - 1981
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.760211306
Subject(s) - materials science , polyolefin , compression molding , composite material , polypropylene , polyethylene , molding (decorative) , ternary operation , scanning electron microscope , polymer blend , epdm rubber , copolymer , mold , polymer , natural rubber , layer (electronics) , computer science , programming language
The morphology of binary and ternary polyolefin blends of polypropylene (PP), ethylene‐propylene‐diene terpolymer (EPDM) and polyethylene (PE) following processing by injection and compression molding has been examined by optical and scanning electron microscopy. Internal surfaces were generated by low temperature fracture and etching with cyclohexane. In binary blends, droplets of EPDM are elongated in the flow direction within 400μm of the mold surface in injection molding, yielding a skin region which is distinct from an isotropic core containing spherical EPDM inclusions. Spherical droplets of EPDM or PE in binary blends with PP increase in size with increasing compression molding time. In ternary blends, spherical inclusions containing both EPDM and PE are dispersed in PP. With increasing compression molding time, EPDM separates from PE and concentrates at the outer edges of the PE inclusion, effectively isolating PE from the PP matrix.