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| Titel: |
Relaxation Behavior of Poly(N-monosubstituted Methacrylamides) |
| Auteur: |
Kolarˆik, J. Kopecek, J. Vacik, J. Janacek, J. |
| Verschenen in: |
International journal of polymeric materials |
| Paginering: | Jaargang 5 (1976) nr. 1-2 pagina's 89-97 |
| Jaar: |
1976-07-01 |
| Inhoud: |
A free-oscillating torsional pendulum was used to investigate the effect of substituents R on the dynamic mechanical relaxation behavior of poly(N-monosubstituted methacrylamides) in the temperature interval from -196 to 130°C. A comparison with the corresponding polymethacrylates shows that the relaxation motion of the side groups R, which gives rise to the low temperature dispersion (below - 130°C), is virtually independent of whether R is attached to COO or CONH groups. On the other hand the obtained data give evidence that a strong intermolecular interaction and high steric hindrances suppress the onset of the motion of CONH-R side chains as a whole. For the same reason the glass transition temperature of the poly(N-monosubstituted methacrylamides) is about 100°C higher than that of the corresponding polymethacrylates. The incorporation of low molecular weight substances leads to reduction of the low-temperature dispersion and to formation of a new secondary dispersion at a temperature of about - 100°C (1 Hz); with increasing concentration of the diluent this new dispersion becomes more intensive and shifts toward lower temperatures. These and the earlier data indicate that the transformation of the secondary relaxation processes due to the effect of diluents is likely of more general character. |
| Uitgever: |
Taylor & Francis |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 9 van 11 gevonden artikelen
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