Joint effects of long-chain branching and specific nucleation on morphology and thermal properties of polypropylene blends

The influence of long-chain branching and specific β-nucleation on polymorphic composition, melting and crystallization, and morphology of polypropylene blends were investigated by wide-angle X-ray scattering, differential scanning calorimetry, and scanning electron microscopy. Linear polypropylene...

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Bibliographic Details
Main Authors: L. Gajzlerova, J. Navratilova, A. Ryzi, T. Slabenakova, R. Cermak
Format: Article
Language:English
Published: Budapest University of Technology and Economics 2020-10-01
Series:eXPRESS Polymer Letters
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Online Access:http://www.expresspolymlett.com/letolt.php?file=EPL-0010572&mi=cd
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Summary:The influence of long-chain branching and specific β-nucleation on polymorphic composition, melting and crystallization, and morphology of polypropylene blends were investigated by wide-angle X-ray scattering, differential scanning calorimetry, and scanning electron microscopy. Linear polypropylene and long-chain branched polypropylene were used for the preparation of blends in various proportions. N,N′-dicyclohexylnaphthalene-2,6-dicarboxamide was introduced (0 or 0.03 wt%) as a β-specific nucleating agent into prepared blends. It was found that LCB-PP strongly induces γ-phase formation in the blends and suppresses the nucleation activity of a β-specific nucleating agent. Blends containing a predominant amount of α- and γ-phases showed higher thermodynamic stability within melting, as compared to the samples rich in β-phase. During crystallization, LCB-PP in the blends increases nucleation density by self-seeding effect, manifesting itself in the shift of crystallization temperature. β-phase in the blends is distinctly separated in spherulites, while α- and γ-phases coexist on the lamellae level.
ISSN:1788-618X