| Autor: |
Čačković, H., Loboda-Čačković, J., Hosemann, R., Weick, D. |
| Zdroj: |
Colloid & Polymer Science; Oct1974, Vol. 252 Issue 10, p812-818, 7p |
| Abstrakt: |
A new statistical theory leads to a simple relation [eq. 3] between the crystallinity and the branching ratio e for polyethylene (PE) cold drawn to the natural draw ratio. Three assumptions are made: If m is the mean number of monomers in chain direction within one paracrystal, then this optimum can never be attained, if mε during the whole process of necking is larger than 1. Now the theory gives no answer and the experiments give a crystallinity of ∼ 0.55 for all observed cases. For mε < 1, where the optimal crystallinity is established the volume occupied by the direct backfolds is about two third of the volume of the amorphous phase. Comparison with the crystallinity obtained from other methods proves that the superstructure consists of paracrystalline lamellae and not of clusters of lamellae imbedded into a amorphous matrix. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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