Polypropylene Filled with Silica Modified by Organosilanes with Different Lengths of Alkyl Chain

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28110%2F24%3A63579980" target="_blank" >RIV/70883521:28110/24:63579980 - 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

Polypropylene Filled with Silica Modified by Organosilanes with Different Lengths of Alkyl Chain

Original language description

This study investigates the production, modification, and application of silica (SiO2) particles to enhance the properties of polypropylene (PP) composites. The modification of SiO2 was achieved using various organosilanes, specifically methyltriethoxysilane (C1), propyltriethoxysilane (C3), octyltriehoxysilane (C8), and octadecyltriethoxysilane (C18). The Stöber process facilitated the synthesis of silica particles, and subsequent modification with the alkoxysilanes was confirmed using thermogravimetric analysis (TGA). The PP-SiO2 composites were prepared by melt-mixing process of PP with 0.2 wt. % SiO2. Isothermal crystallization studies revealed that the presence of SiO2, particularly the unmodified variant, significantly influences the crystallization rate of PP. The shortest crystallization half-time (t0.5) was generally observed in PP-SiO2 across various crystallization temperatures, except for PP-SiO2-C1, which exhibited the slowest crystallization. The results suggested that the alkyl chain length of the organosilanes did not consistently affect t0.5. Melting analysis indicated negligible β-phase formation in neat PP and PP-SiO2, regardless of crystallization temperature. However, organophilized mixtures (PP-SiO2-C1, C3, C8, and C18) showed increased β-phase content with decreasing crystallization temperature. Above this threshold, the materials predominantly crystallized into the α-phase, similar to neat PP and PP-SiO2. The nucleation effect, and hence the β-phase formation, was attributed to the presence of organosilane-modified SiO2 particles. This study demonstrates that organophilized silica particles can induce β-phase formation in isotactic polypropylene, with the alkyl chain length of the organosilanes playing a critical role. The β-phase onset was observed at crystallization temperatures below 134 °C, highlighting the potential of organosilane-modified SiO2 in tailoring the crystallization behaviour and phase composition of polypropylene composites.

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