Effects of molecular weight on the perforation impact behavior of injection-molded plaques of α- and β-phase isotactic polypropylenes

J. Karger-Kocsis, E. Moos, I. Mudra, J. Varga

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

This study was devoted to the instrumented falling weight impact (IFWI) behavior of injection-molded α- and β-phase isotactic polypropylene (iPP) homopolymers. The perforation impact response of iPP with various melt flow indices (MFIs), and thus molecular weight (MW) characteristics, was studied at two different temperatures (T = 23 °C and T = -40 °C) and incident impact speeds (vinc = 5 and 10 m/s). The impact resistance of β-iPP was superior to the α- modification. The absolute resistance to perforation increased with increasing MW or decreasing MFI, whereas the relative toughness improvement between the β-and α-iPPs followed an opposite tendency. The molding-induced skin-core morphology did not affect practically the out-of-plane response of the impacted plaques. Changes in the fractograms (viz. force-time curves) under various experimental conditions were traced to variations in the failure mode, showing a competition between radial and circumferential cracking with respect to the clamping ring. In the case of the more ductile α-iPP, circumferential cracking was favored.

Original languageEnglish
JournalJournal of Macromolecular Science - Physics
Volume38
Publication statusPublished - 1999

Fingerprint

Polypropylenes
Molecular weight
Impact resistance
Homopolymerization
Molding
Failure modes
Toughness
Skin
Temperature

ASJC Scopus subject areas

  • Materials Chemistry
  • Polymers and Plastics

Cite this

@article{4550f07f5b6a496491f053da0eafa8b7,
title = "Effects of molecular weight on the perforation impact behavior of injection-molded plaques of α- and β-phase isotactic polypropylenes",
abstract = "This study was devoted to the instrumented falling weight impact (IFWI) behavior of injection-molded α- and β-phase isotactic polypropylene (iPP) homopolymers. The perforation impact response of iPP with various melt flow indices (MFIs), and thus molecular weight (MW) characteristics, was studied at two different temperatures (T = 23 °C and T = -40 °C) and incident impact speeds (vinc = 5 and 10 m/s). The impact resistance of β-iPP was superior to the α- modification. The absolute resistance to perforation increased with increasing MW or decreasing MFI, whereas the relative toughness improvement between the β-and α-iPPs followed an opposite tendency. The molding-induced skin-core morphology did not affect practically the out-of-plane response of the impacted plaques. Changes in the fractograms (viz. force-time curves) under various experimental conditions were traced to variations in the failure mode, showing a competition between radial and circumferential cracking with respect to the clamping ring. In the case of the more ductile α-iPP, circumferential cracking was favored.",
author = "J. Karger-Kocsis and E. Moos and I. Mudra and J. Varga",
year = "1999",
language = "English",
volume = "38",
journal = "Journal of Macromolecular Science - Reviews in Macromolecular Chemistry and Physics",
issn = "1558-3724",
publisher = "Taylor and Francis Ltd.",

}

TY - JOUR

T1 - Effects of molecular weight on the perforation impact behavior of injection-molded plaques of α- and β-phase isotactic polypropylenes

AU - Karger-Kocsis, J.

AU - Moos, E.

AU - Mudra, I.

AU - Varga, J.

PY - 1999

Y1 - 1999

N2 - This study was devoted to the instrumented falling weight impact (IFWI) behavior of injection-molded α- and β-phase isotactic polypropylene (iPP) homopolymers. The perforation impact response of iPP with various melt flow indices (MFIs), and thus molecular weight (MW) characteristics, was studied at two different temperatures (T = 23 °C and T = -40 °C) and incident impact speeds (vinc = 5 and 10 m/s). The impact resistance of β-iPP was superior to the α- modification. The absolute resistance to perforation increased with increasing MW or decreasing MFI, whereas the relative toughness improvement between the β-and α-iPPs followed an opposite tendency. The molding-induced skin-core morphology did not affect practically the out-of-plane response of the impacted plaques. Changes in the fractograms (viz. force-time curves) under various experimental conditions were traced to variations in the failure mode, showing a competition between radial and circumferential cracking with respect to the clamping ring. In the case of the more ductile α-iPP, circumferential cracking was favored.

AB - This study was devoted to the instrumented falling weight impact (IFWI) behavior of injection-molded α- and β-phase isotactic polypropylene (iPP) homopolymers. The perforation impact response of iPP with various melt flow indices (MFIs), and thus molecular weight (MW) characteristics, was studied at two different temperatures (T = 23 °C and T = -40 °C) and incident impact speeds (vinc = 5 and 10 m/s). The impact resistance of β-iPP was superior to the α- modification. The absolute resistance to perforation increased with increasing MW or decreasing MFI, whereas the relative toughness improvement between the β-and α-iPPs followed an opposite tendency. The molding-induced skin-core morphology did not affect practically the out-of-plane response of the impacted plaques. Changes in the fractograms (viz. force-time curves) under various experimental conditions were traced to variations in the failure mode, showing a competition between radial and circumferential cracking with respect to the clamping ring. In the case of the more ductile α-iPP, circumferential cracking was favored.

UR - http://www.scopus.com/inward/record.url?scp=0033364968&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033364968&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0033364968

VL - 38

JO - Journal of Macromolecular Science - Reviews in Macromolecular Chemistry and Physics

JF - Journal of Macromolecular Science - Reviews in Macromolecular Chemistry and Physics

SN - 1558-3724

ER -