Abstract
The rate/temperature dependent fracture behaviour of plain and glass-filled polystyrene has been investigated over the crack speed (a) range of 10-6 to 10-2 m sec-1 and in the temperature (T) range of 296 to 363 K. The Kc (a, T) relationships obtained, where Kc is the stress intensity factor at fracture, are shown to follow those given by the Williams/Marshall relaxation crack growth model and the toughness-biased rate theory. Crack propagation in both materials is shown to be controlled by a β-relaxation molecular process associated with crazing. Crack instabilities observed in plain polystyrene are analysed successfully in terms of isothermal-adiabatic transitions at the crack tip. Fracture initiation experiments are also conducted in which the effects of organic liquids on the fracture resistances of both plain/glass-filled polystyrene have been determined. Good correlations between Ki2 (Ki being the crack initiation stress intensity factor) and δs, solvent solubility parameter, of various liquid environments have been obtained, which give a minimum Ki2 value at δs ≈ δp, where δp is the solubility parameter of the polymer. For a given temperature, liquid environment and crack speed, the glass-filled polystyrene is shown to possess greater resistances to crack propagation than plain polystyrene.
Original language | English |
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Pages (from-to) | 677-688 |
Number of pages | 12 |
Journal | Journal of Materials Science |
Volume | 11 |
Issue number | 4 |
DOIs | |
Publication status | Published - Apr 1976 |
Externally published | Yes |
ASJC Scopus subject areas
- Ceramics and Composites
- Materials Science (miscellaneous)
- General Materials Science
- Mechanics of Materials
- Mechanical Engineering
- Polymers and Plastics