The morphology, chain structure and fracture behaviour of high-density polyethylene
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High-density polyethylene (HDPE) is being used more and more in critical long-term applications. For this reason it is important to have a strong understanding of those parameters which control the fracture behaviour of HDPE. In Part I of this work, fracture results were presented for eleven HDPE samples tested using a tensile testing machine. Such short-term tests do not accurately reflect the in-service loads on HDPE components, which tend to be low and static. It is, therefore, important to perform fracture tests under long-term static loads. The results of such testing are presented in this paper. The resistance to static fatigue was found to be most strongly dependent on molecular weight. Short branch concentration and short branch length were also found to exert an influence on the resistance to static fatigue. This result is similar to the findings presented in Part I of this work. However, there is some evidence that molecular weight influences fracture behaviour to a greater extent in the long-term tests. Notwithstanding, the similarity between the short-term and long-term results is important. It means that an early indication of the long-term performance of HDPE resins can be obtained from rapid comparative tests conducted using a tensile testing machine.
KeywordsFracture Behaviour HDPE Fracture Test Tensile Testing Machine Static Fatigue
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- 1.B. J. EGAN and O. DELTAYCKI, J. Mater. Sci. (1994) submitted.Google Scholar
- 3.J. A. KIES and B. J. CLARK, in “Proceedings of the 2nd International Conference on Fracture”, Brighton, April 1969, edited by P. L. PRATT (Chapman and Hall, London, 1969) p. 483.Google Scholar
- 8.J. M. CRISSMAN and L. J. ZAPAS, in “Durability of Macromolecular Materials”, edited by R. K. Eby (ACS Symposium Series 95, Washington, DC, 1979) p. 289.Google Scholar
- 12.G. P. MARSHALL, Plast. Rubber Proc. Appl. 2 (1982) 169.Google Scholar
- 18.L. MANDELKERN and A. J. PEACOCK, in “Proceedings of an International Course and Conference on the Interfaces between Mathematics, Chemistry and Computer Science”, Dubrovnik, Yugoslavia, 1987, edited by R. C. LACHER (Elsevier Applied Science, New York, 1988) p. 201.Google Scholar