| Autor: |
A.L. Yefremov, N.M. Kotov, Yu.A. Zubov, V.I. Selikhova, N.F. Bakeyev, G.P. Belov, V.A. Sokol'skii, M.B. Konstantinopol'skaya, A.N. Ozerin, V.S. Shchirets |
| Rok vydání: |
1975 |
| Předmět: |
|
| Zdroj: |
Polymer Science U.S.S.R.. 17:1312-1317 |
| ISSN: |
0032-3950 |
| DOI: |
10.1016/0032-3950(75)90395-0 |
| Popis: |
A study was made by differential thermal analysis (DTA) of the effect of pressure up to 8000 kg/cm 2 on melting and crystallization of linear polyethylene (PE). It was shown that thermograms of melting and crystallization at pressures of over 4000 kg/cm 2 are characterized by the presence of two peaks. The existence of two peaks is a general phenomenon for isotropic and oriented specimens, single crystals and specimens containing crystals with straightened chains. An X-ray study shows that c -axial orientation of elongated specimens during annealing at a pressure of 7000 kg/cm 2 only disappears after the second endothermic peak, i.e. this peak corresponds to the final melting point. The presence of a low temperature peak points to the existence of an intermediate high pressure phase. A phase diagram was plotted under high pressure using DTA results, for isotropic and oriented PE samples up to 8000 kg/cm 2 . A study was made of the effect of the degree of elongation on melting PE under a pressure of 7000 kg/cm 2 . |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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