| Autor: |
Yu B, Jiang Bz, Luo Yx, Ding Mx, Hanxi Yang |
| Rok vydání: |
1993 |
| Předmět: |
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| Zdroj: |
Acta Physico-Chimica Sinica. 9:604-609 |
| ISSN: |
1000-6818 |
| Popis: |
The radiation-induced chain-scission and racemization of isotactic poly(methylmethacrylate)(iso-PMMA) in amorphous and semi-crystalline state as well as in solution have been studied with nuclear magnetic resonance and molar mass deter-mination. It is shown that the chain-scission is dominant for iso-PMMA in dilute solution while the racemization reaction is not favorable in this case. On the contrary, the racemization is favorable when iso-PMMA was irradiated in its crystalline state while chain-scission is not. Such experimental results could be well explained by the mobility of molecules and "cage effect". The hypothesis, we proposed previously that the chain-scission, racemization and recombination are in competition and the final result depends on the state of molecular motion at which iso-PMMA was irradiated, has been verified verified once again. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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