Fatigue crack propagation and related failure in modified, andhydride-cured epoxy resins

J. Karger-Kocsis, K. Friedrich

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

The fatigue crack propagation (FCP) of neat and modified, anhydridecured epoxy resin (EP) was studied in tensile-tensile mode at ambient temperature. As modifiers, liquid carboxyl-terminated acrylonitrile-butadiene (CTBN) and silicon rubber (SI) dispersions were used. The latter modifier in a defined particle size distribution was produced by a special latex technology, whereas the former developed in situ in the EP by phase separation during curing. The dispersion-type morphologies of the EPs were characterized by using polished sections and viewing them in a scanning electron microscope (SEM). The resulting frequency distribution curves were compared with those analyzed from fatigue fracture surfaces. Probable failure mechanisms were also studied by SEM-fractography. Both modifiers improved the resistance to FCP by shifting the curves to higher stress intensity factor ranges (ΔK) in relation to the reference curve determined for the neat EP-matrix. The failure mechanisms, summarized also schematically, differed basically for the various modifiers. According to this, rubber-induced cavitation and shear yielding of the matrix seemed to be dominant for CTBN, which did not affect the principal crack plane. In contrast to this, crack bifurcation, branching and, hence, a forced deviation in the fatigue crack path induced by debonded SI-particles in the EP-matrix were concluded for the SI modifier. The common use of both modifiers yielded a positive synergistic effect due to the superposition of the above failure mechanisms.

Original languageEnglish
Pages (from-to)549-562
Number of pages14
JournalColloid & Polymer Science
Volume270
Issue number6
DOIs
Publication statusPublished - Jun 1992

Fingerprint

Epoxy Resins
Rubber
epoxy resins
crack propagation
Fatigue crack propagation
rubber
Epoxy resins
Silicon
Acrylonitrile
cracks
acrylonitriles
butadiene
Butadiene
silicon
Electron microscopes
curves
matrices
electron microscopes
fractography
Cracks

Keywords

  • CTBN modifier
  • Epoxy resin
  • failure models
  • fatigue crack propagation (FCP)
  • fractography
  • fracture mechanics
  • liquid nitrile rubber (NBR)
  • particle toughening
  • silicon rubber dispersion
  • toughened epoxy resin

ASJC Scopus subject areas

  • Polymers and Plastics
  • Materials Chemistry
  • Physical and Theoretical Chemistry
  • Colloid and Surface Chemistry

Cite this

Fatigue crack propagation and related failure in modified, andhydride-cured epoxy resins. / Karger-Kocsis, J.; Friedrich, K.

In: Colloid & Polymer Science, Vol. 270, No. 6, 06.1992, p. 549-562.

Research output: Contribution to journalArticle

@article{493af679637640c08a3709d791348f30,
title = "Fatigue crack propagation and related failure in modified, andhydride-cured epoxy resins",
abstract = "The fatigue crack propagation (FCP) of neat and modified, anhydridecured epoxy resin (EP) was studied in tensile-tensile mode at ambient temperature. As modifiers, liquid carboxyl-terminated acrylonitrile-butadiene (CTBN) and silicon rubber (SI) dispersions were used. The latter modifier in a defined particle size distribution was produced by a special latex technology, whereas the former developed in situ in the EP by phase separation during curing. The dispersion-type morphologies of the EPs were characterized by using polished sections and viewing them in a scanning electron microscope (SEM). The resulting frequency distribution curves were compared with those analyzed from fatigue fracture surfaces. Probable failure mechanisms were also studied by SEM-fractography. Both modifiers improved the resistance to FCP by shifting the curves to higher stress intensity factor ranges (ΔK) in relation to the reference curve determined for the neat EP-matrix. The failure mechanisms, summarized also schematically, differed basically for the various modifiers. According to this, rubber-induced cavitation and shear yielding of the matrix seemed to be dominant for CTBN, which did not affect the principal crack plane. In contrast to this, crack bifurcation, branching and, hence, a forced deviation in the fatigue crack path induced by debonded SI-particles in the EP-matrix were concluded for the SI modifier. The common use of both modifiers yielded a positive synergistic effect due to the superposition of the above failure mechanisms.",
keywords = "CTBN modifier, Epoxy resin, failure models, fatigue crack propagation (FCP), fractography, fracture mechanics, liquid nitrile rubber (NBR), particle toughening, silicon rubber dispersion, toughened epoxy resin",
author = "J. Karger-Kocsis and K. Friedrich",
year = "1992",
month = "6",
doi = "10.1007/BF00658286",
language = "English",
volume = "270",
pages = "549--562",
journal = "Kolloid Zeitschrift",
issn = "0303-402X",
publisher = "Springer Verlag",
number = "6",

}

TY - JOUR

T1 - Fatigue crack propagation and related failure in modified, andhydride-cured epoxy resins

AU - Karger-Kocsis, J.

AU - Friedrich, K.

PY - 1992/6

Y1 - 1992/6

N2 - The fatigue crack propagation (FCP) of neat and modified, anhydridecured epoxy resin (EP) was studied in tensile-tensile mode at ambient temperature. As modifiers, liquid carboxyl-terminated acrylonitrile-butadiene (CTBN) and silicon rubber (SI) dispersions were used. The latter modifier in a defined particle size distribution was produced by a special latex technology, whereas the former developed in situ in the EP by phase separation during curing. The dispersion-type morphologies of the EPs were characterized by using polished sections and viewing them in a scanning electron microscope (SEM). The resulting frequency distribution curves were compared with those analyzed from fatigue fracture surfaces. Probable failure mechanisms were also studied by SEM-fractography. Both modifiers improved the resistance to FCP by shifting the curves to higher stress intensity factor ranges (ΔK) in relation to the reference curve determined for the neat EP-matrix. The failure mechanisms, summarized also schematically, differed basically for the various modifiers. According to this, rubber-induced cavitation and shear yielding of the matrix seemed to be dominant for CTBN, which did not affect the principal crack plane. In contrast to this, crack bifurcation, branching and, hence, a forced deviation in the fatigue crack path induced by debonded SI-particles in the EP-matrix were concluded for the SI modifier. The common use of both modifiers yielded a positive synergistic effect due to the superposition of the above failure mechanisms.

AB - The fatigue crack propagation (FCP) of neat and modified, anhydridecured epoxy resin (EP) was studied in tensile-tensile mode at ambient temperature. As modifiers, liquid carboxyl-terminated acrylonitrile-butadiene (CTBN) and silicon rubber (SI) dispersions were used. The latter modifier in a defined particle size distribution was produced by a special latex technology, whereas the former developed in situ in the EP by phase separation during curing. The dispersion-type morphologies of the EPs were characterized by using polished sections and viewing them in a scanning electron microscope (SEM). The resulting frequency distribution curves were compared with those analyzed from fatigue fracture surfaces. Probable failure mechanisms were also studied by SEM-fractography. Both modifiers improved the resistance to FCP by shifting the curves to higher stress intensity factor ranges (ΔK) in relation to the reference curve determined for the neat EP-matrix. The failure mechanisms, summarized also schematically, differed basically for the various modifiers. According to this, rubber-induced cavitation and shear yielding of the matrix seemed to be dominant for CTBN, which did not affect the principal crack plane. In contrast to this, crack bifurcation, branching and, hence, a forced deviation in the fatigue crack path induced by debonded SI-particles in the EP-matrix were concluded for the SI modifier. The common use of both modifiers yielded a positive synergistic effect due to the superposition of the above failure mechanisms.

KW - CTBN modifier

KW - Epoxy resin

KW - failure models

KW - fatigue crack propagation (FCP)

KW - fractography

KW - fracture mechanics

KW - liquid nitrile rubber (NBR)

KW - particle toughening

KW - silicon rubber dispersion

KW - toughened epoxy resin

UR - http://www.scopus.com/inward/record.url?scp=0026882667&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026882667&partnerID=8YFLogxK

U2 - 10.1007/BF00658286

DO - 10.1007/BF00658286

M3 - Article

AN - SCOPUS:0026882667

VL - 270

SP - 549

EP - 562

JO - Kolloid Zeitschrift

JF - Kolloid Zeitschrift

SN - 0303-402X

IS - 6

ER -