Janevski, Aco and Bogoeva-Gaceva, Gordana and Najdoski, Metodija and Stefov, Viktor (2018) Isothermal Crystallization of Isotactic Polypropylene Nucleated with Pimelates of Earth-Alkaline Elements. In: 25th Congress of SCTM, 19-22 Sept 2018, Ohrid, R. Macedonia.
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Abstract
Ba, Sr, Ca and Mg pimelates were used as nucleators for the crystallization of isotactic polypropylene. The pimelates were synthesized as described earlier [1] and they were obtained as white powders. Their average grain size and distribution were determined, and for Ca- and Ba-pimelates the grain size was less than 10 m, while larger dimensions were found for Mg- and Sr-pimelates (29 and 22 m). Isothermal crystallization of polypropylene was analyzed by DSC. The crystallization was carried out at the Tc in the range from 397K to 406 K. Based on the determined values for the enthalpy of crystallization, the extent of crystallization (crystal conversion) was calculated and the half-time of crystallization (t0.5) was determined and used as a parameter to compare the rate of crystallization in differently nucleated systems. It was shown that the value of t0.5 for Ca-pimelate nucleated polyprolylene was lower than for all other nucleated systems. The content of the β-crystalline phase in polypropylene nucleated with different pimelates has a decreasing tendency with the increasing of crystallization temperature, Tc. The equilibrium melting temperature for the nucleated polypropylene was in the range T0m=446-455 K, lower than for non-nucleated isotactic polypropylene (460 K).
| Item Type: | Conference or Workshop Item (Poster) |
|---|---|
| Subjects: | Engineering and Technology > Chemical engineering Natural sciences > Chemical sciences Engineering and Technology > Materials engineering |
| Divisions: | Faculty of Technology |
| Depositing User: | Aco Janevski |
| Date Deposited: | 13 Dec 2018 08:45 |
| Last Modified: | 13 Dec 2018 08:45 |
| URI: | https://eprints.ugd.edu.mk/id/eprint/20956 |
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