| Autor: |
A.S. Lykin, L.I. Dashevskii, S.M. Kavun |
| Rok vydání: |
1976 |
| Předmět: |
|
| Zdroj: |
Polymer Science U.S.S.R.. 18:3154-3161 |
| ISSN: |
0032-3950 |
| DOI: |
10.1016/0032-3950(76)90430-5 |
| Popis: |
A study has been made of regularities of the chemical relaxation of stress in crosslinked polydieneureaurethanes under conditions whereby hydrocarbon chains of the elastomers remain intact. It was found that in the temperature interval 110–140° stress relaxation in these polymers in vacuo is due to the breakdown of biurete or allophanate crosslinks in the three-dimensional network, whereas no breakdown of the urea and allophanate crosslinks occurs under these conditions. The breakdown of network points during stress relaxation at 130° in vacuo is accompanied by secondary crosslinking with formation of crosslinks that are no longer susceptible to breakdown. The rates of formation and breakdown of crosslinks are commensurate. The stress decay rate depends on deformation given changes in breaking elongation within limits of 50–150%. Possible explanations of this effect are suggested. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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