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Post-polymerační modifikace polyolefinů pro přípravu hydroxylovaných makroiniciátorů / Post-polymerization modification of polyolefins for the preparation of hydroxylated macroinitiators

The diploma thesis deals with post-polymerization hydroxylation of polypropylene in solid state. Regarding the literature review, polypropylene was hydroxylated by radical grafting in aqueous solution of potassium persulfate at 100 °C, under nitrogen atmosphere for 60 minutes. Hydroxylation of polypropylene was performed at different concentrations of potassium persulfate (1; 5; 10 mol. %) and two different water/potassium persulfate molar ratios. The effects of reaction system composition and reaction conditions on reaction efficiency, extent of side reactions, thermal and rheological properties of hydroxylated polypropylene were evaluated. The presence and concentration of hydroxyl groups on polypropylene surface was determined by structural analysis (FTIR, XPS), while the highest efficiency was achieved in the presence of nonionic wetting agents, using 10 mol. % potassium persulfate and at lower water/potassium persulfate molar ratio. Based on changes in polypropylene structure, the modification took place mainly in the amorphous phase of the polymer. In addition to hydroxylation, concurrent side reactions have been reported, in particular the oxidation of wetting agents and polypropylene, which has resulted in chain cleavage, reducing the average molecular weight of the polypropylene.

Identiferoai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:432943
Date January 2020
CreatorsBoldovjaková, Tatiana
ContributorsKučera, František, Petruš, Josef
PublisherVysoké učení technické v Brně. Fakulta chemická
Source SetsCzech ETDs
LanguageSlovak
Detected LanguageEnglish
Typeinfo:eu-repo/semantics/masterThesis
Rightsinfo:eu-repo/semantics/restrictedAccess

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