| Autor: |
Julian F. Johnson, Edward M. Barrall, Joseph L. Haberfeld, Richard C. Gaskill |
| Rok vydání: |
1977 |
| Předmět: |
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| Zdroj: |
Thermochimica Acta. 18:95-99 |
| ISSN: |
0040-6031 |
| DOI: |
10.1016/0040-6031(77)80036-1 |
| Popis: |
The expansion properties of samples of filled and unfilled, crosslinked low density polyethylene and ethylene-propylene insulation material have been studied by thermomechanical analysis. Both axial and radial expansion coefficients of the preformed insulation were evaluated. Release of the frozen in strains in the axial direction was noted. Reheating directly after cooling of a sample did not indicate rapid recovery of frozen in strains. Axial strains were found to be translated to the radial direction as would be expected. However, in crosslinked material the return of axial stress was noted in as little as a week after heating. Holding the sample at elevated temperatures (below the melting or glass point) was found to accelerate the rate of stress build up. It is postulated that this effect may be due to interaction between crosslinks and crystallizing regions. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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