The Effect of the Density and Nature of Spatial Network in Elastomers on Their Viscoelastic Characteristics
| Autor: | B. M. Gorelik, V. I. Gartsman, G. V. Vinogradov |
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| Rok vydání: | 1974 |
| Předmět: | |
| Zdroj: | International Journal of Polymeric Materials. 3:165-175 |
| ISSN: | 1563-535X 0091-4037 |
| Popis: | We have studied the effect of the density of the networks formed by fluctuating entanglements and chemical crosslinking on the relationships between the circular frequency ω and the storage and loss moduli, G' and G”, for polybutadienes of narrow and wide molecular weight distributions (the ratio Mw/Mn varied from 1.1 to 3.35) and different microstructure. Polybutadienes were crosslinked by thermal, radiation, and sulphur vulcanization. With increasing density v of a network of chemical crosslinks, which is characterized by the average molecular weight of a chain length (Me ), pseudo-equilibrium plateau extends to the side of low frequencies with a certain small increase of its level. This increase becomes noticeable when Me is approximately equal to the average molecular weight Me of the chain length between the fluctuating entanglements of an uncrosslinked elastomer. At the same time the maxima on the curves of G”(ω) are smoothed out and the losses reduce to negligibly small values with decreas... |
| Databáze: | OpenAIRE |
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