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High modulus of isotactic polypropylene attained by coextrusion with atactic polystyrene
Author(s) -
Verbraak C. L. J. A.,
Van Dam J.,
Van Der Vegt A. K.
Publication year - 1985
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.760250709
Subject(s) - materials science , polypropylene , tacticity , composite material , polystyrene , extrusion , polymer , modulus , polymerization
Orientation‐induced crystallization of crystallizable polymer melts can occur, under certain conditions, during flow through converging channels. Attempts have been made to achieve this phenomenon in a two‐phase system, i.e., during simultaneous extrusion of a continuous concentric core of polypropylene within a polystyrene matrix through a conical duct. On one occasion, using Carlona P SY6100 (MFI = 11.0) with Hostyren N2000‐V‐01 (MFI = 25.0), a highly oriented polypropylene thread with a modulus of 14.6 GPa and a melting point of 178°C was extruded at a die temperature of approximately 170°C and a pressure lower than 40 MPa. It is, in principle, possible to form highly oriented, fiber‐like structures as reinforcing elements in a polymer matrix.