Thermal behavior of ethylene/1-octene copolymer fractions at high temperatures: Effect of hexyl branch content
| Autor: | Abbas Kebritchi, Mehdi Nekoomanesh, Fereidoun Mohammadi, Hossein Khonakdar, Udo Wagenknecht |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | Polyolefins Journal, Vol 6, Iss 2, Pp 127-138 (2019) |
| Druh dokumentu: | article |
| ISSN: | 2322-2212 2345-6868 |
| DOI: | 10.22063/poj.2019.2295.1123 |
| Popis: | In this work, the effect of hexyl branch content on thermal behavior of a fractionated ethylene/1-octene copolymer with emphasis on high temperatures was investigated. The ethylene/1-octene copolymer was carefully fractionated to different fractions with homogenous hexyl branch (HB) content by preparative temperature rising elution fractionation (P-TREF) method. The P-TREF fractions were thermally analyzed via differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and evolved gas analysis (EGA). The P-TREF profile showed a short chain branch distribution (SCBD) of around 1.24. A linear relationship between P-TREF elution temperature (ET) and methylene sequence length (MSL) was presented. The DSC curves exhibited a monolithically increase in melting temperature (Tm) as well as crystallization temperature (Tc) by decreasing short chain branch (SCB) content. The calculated values of lamellae thickness suggested a linear function of SCB content and Tm. The TGA studies of P-TREF fractions depicted a two-stage thermal degradation behavior: pre-degradation and main degradation stages. Tmax for both pre-degradation and main degradation stages was increased for fractions with less hexyl branch content. As an interesting point the pre-degradation stage was found more intensified for more linear fractions. The concentration of main products was found to be affected by the content of hexyl branches using Py-GC-MS. |
| Databáze: | Directory of Open Access Journals |
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