Long Chain-branched Polypropylene as a Nucleating Agent for Linear Polypropylene

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28110%2F24%3A63579959" target="_blank" >RIV/70883521:28110/24:63579959 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Long Chain-branched Polypropylene as a Nucleating Agent for Linear Polypropylene

Original language description

Presented study deals with the influence of an addition of long chain-branched polypropylene (LCB-PP) at minor concentration on the crystallization and polymorphism of linear polypropylene (L-PP) without/with β-nucleating agent. The concentration of LCB-PP was in the range of 0.005 to 1 wt. %. This low concentration was chosen in view of the possibility of using LCB-PP as a nucleating agent for L-PP. The crystallinity and polymorphic composition of the blends were investigated by wide-angle X-ray diffraction, thermal behavior by differential scanning calorimetry, and haze by spectrophotometry. It was found that LCB-PP, already at very low contents, significantly suppresses the efficiency of the nucleating agent, decreasing the content of the trigonal β-phase while initiating the formation of the orthorhombic γ-phase. A similar trend is observed for non-nucleated samples; however, the content and subsequently the decrease of the β-phase is not as significant. The presence of LCB-PP leads to crystallization at higher temperature and thus accelerates the overall crystallization. As little as 0,005 wt. % of LCB-PP leads to an increase in the crystallization temperature of L-PP of more than 5 °C and with the addition of 0.2 wt. % up to 10 °C, which is comparable to the crystallization temperature of nucleated L-PP (124 °C). LCB-PP increases nucleation density by self-seeding effect, manifesting itself in the shift of crystallization temperature.Haze measurements on a spectrophotometer showed that pure L-PP blends with LCB-PP generally have much lower haze than blends with nucleating agent. These observations demonstrate the effectiveness of LCB-PP as an α-nucleating agent with concentrations as low as 0.2 wt.%.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

10404 - Polymer science

Project

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Continuities

V - Vyzkumna aktivita podporovana z jinych verejnych zdroju

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů