GPC and physico-chemical characterization of polypropylenes obtained on II generation titanium catalys (in Engish)
Polydispersity of the polypropylenes produced in the Mazovian Refinery and Petrochemical Works Petrochemia-Płock on two titanium catalysts, Lynx 900 (USA) and „microspherical" (Russia), were investigated by the GPC method. Again, the propylene prepolymers isolated from the titanium catalysts were analyzed by the GPC method. The parameters of the GPC analysis were established. Results proved they were correct. The molecular characteristics of the prepolymers from (i) Lynx 900 and (ii) „microspherical" catalysts were different: (i) M„ - 8.0 • 103 g/mol and Mw/Mn = 5.4; (ii) M„ = 23.8 1 103 g/mol and Mw/Mn - 18.4. The GPC distribution plots for these two prepolymers were quite different. Independently of the different polydispersities of the prepolymers, the film- -grade polypropylenes (F-401) obtained on the Lynx 900 and the „microspherical" catalysts had similar physico-chemical properties and polydispersities (Mw/Mn = 4.5—6.1). They were characterized by narrow particle size distributions and the granulometric distributions of the two polymers were similar. The physico-chemical property data of the two polypropylenes (melting flow index, yield point, softening point and isotacticity index) were close or even better than those required by the Polish Standard BN-79/6364-03. This is presumably due to the relatively low polydispersity of those polymers.
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