Publication detail

Effect of in-situ formed core–shell inclusions on the mechanical properties and impact fracture of polypropylene

JANČÁŘ, J. ŽÍDEK, J.

Original Title

Effect of in-situ formed core–shell inclusions on the mechanical properties and impact fracture of polypropylene

Type

journal article in Web of Science

Language

English

Original Abstract

To obviate the reduction of stiffness in rubber toughened and yield strength in rigid particle toughened iPP, various strategies were adopted. Here, we report on the static and impact properties of isotactic polypropylene (iPP) with in situ formed (rigid thermotropic liquid crystalline core)-(soft copolymer shell) inclusions (RCSS inclusions). We found that, at constant soft shell thickness (t(s)) and stiffness (E-s), the elastic modulus of iPP/RCSS (E-c) increased with the total RCSS volume fraction (nu(RCSS)), and, at constant nu(RCSS), the E-c increased with E-s. At constant ts and Es, the yield strength of iPP/RCSS (sigma(yc)) decreased with the nu(RCSS) and, at constant nu(RCSS) and t(s), the sigma(yc) decreased with E-s in an agreement with the simple micromechanics models of Matonis and Small. At small nu(RCSS), the changes in E-c and sigma(yc) with nu(RCSS) contributed simultaneously to the significant enlargement of the crack tip plastic zone size, enhancing the impact fracture toughness in terms of the apparent critical strain energy release rate (G(c)'), substantially, without significantly reducing stiffness and yield strength. The SEM fractography revealed extension of the RCSS inclusions into fibrous shape providing an additional means for dissipation of mechanical energy stored in the fracturing solid. Experimental data agreed reasonably well with the prediction based on a simple mixed mode fracture model proposed earlier.

Keywords

Polypropylene, Core–shell, Liquid crystalline polymer, Ionomer, Impact fracture

Authors

JANČÁŘ, J.; ŽÍDEK, J.

RIV year

2015

Released

11. 8. 2015

ISBN

0014-3057

Periodical

European Polymer Journal

Year of study

71

Number

7023

State

United Kingdom of Great Britain and Northern Ireland

Pages from

221

Pages to

230

Pages count

10

BibTex

@article{BUT115746,
  author="Josef {Jančář} and Jan {Žídek}",
  title="Effect of in-situ formed core–shell inclusions on the mechanical properties and impact fracture of polypropylene",
  journal="European Polymer Journal",
  year="2015",
  volume="71",
  number="7023",
  pages="221--230",
  doi="10.1016/j.eurpolymj.2015.07.057",
  issn="0014-3057"
}