Abstract
The J integral analysis of compact tension samples has been used to evaluate plane strain fracture toughness of various polyethylenes at room temperature. Crack propagation commences from a razor notch in high-density polyethylene at JIc = 1.7 kJ m-2. Plastic deformation is confined to a small craze region (about 300 μm long, 20 μm high) through which the crack subsequently propagates. A tough copolymer of PE3408 material resists crack advance until JIc = 8.2 kJ m-2. Here again crack propagation is through a craze, though craze length exceeds 1 mm. Toughness is also imparted by the formation of shear bands near the notch tip. Low-density polyethylene does not really fracture under the present test conditions; this material responds by general yielding and blunting of the notch tip.
Original language | English (US) |
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Pages (from-to) | 1440-1446 |
Number of pages | 7 |
Journal | Polymer |
Volume | 32 |
Issue number | 8 |
DOIs | |
State | Published - 1991 |
Funding
ACKNOWLEDGEMENTS This research was supported by the Gas Research InstituteB, asicS cienceD ivision( ContracNt o. 5084-260-1051). We thank Professor B. Moran for helpful discussionsa nd Dr L. Wild for the molecular-weight determinations.
Keywords
- fracture toughness
- morphology
- polyethylenes
ASJC Scopus subject areas
- Organic Chemistry
- Polymers and Plastics
- Materials Chemistry