The Relationship between Supermolecular Structure and Mechanical Properties of Polypropylene Blends

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28110%2F24%3A63579919" target="_blank" >RIV/70883521:28110/24:63579919 - 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

The Relationship between Supermolecular Structure and Mechanical Properties of Polypropylene Blends

Original language description

The study presented here evaluates the connections between chain branching, specific nucleation, and the end-use properties of polypropylene blends. These blends consist of linear polypropylene (L-PP) and long-chain branched polypropylene (LCB-PP), modified using a specific β-nucleating agent (NA). Specimens with varying content of LCB-PP (0, 1, 2, 5, 10, 20, 50, and 100 wt. %), without and with (0.03 wt. %) the NA, were manufactured under complex flow conditions via injection moulding. Wide-angle X-ray scattering was utilized to analyse X-ray patterns of both the skin and core of the specimens, assessing overall crystallinity and quantities of distinct polymorphs. The mechanical behaviours, specifically tensile tests and impact toughness, were investigated with regard to the industrial use of the blends. Based on the results, the growing amounts of LCB-PP and γ-phase in the blends are reflected by both increased crystallinity and improved mechanical properties. Even 1 wt. % of LCB-PP in the blend significantly influences the crystallization behaviour and crystalline composition of the injectionmoulded samples. This modification of supermolecular structure results in improved mechanical properties, specifically yield stress and Young&apos;s modulus. Already with the addition of 20 wt. % of LCB-PP it is possible to achieve a 30 % increase in modulus compared to pure L-PP. In contrast, the impact toughness is not considerably influencedby the composition of the blends. The exception is the nucleated L-PP showing double increase compared to its non-nucleated counterpart, which can be attributed to the higher β-crystallites content. Higher LCB-PP content leads to lower elongation at break. The influence of NA addition on the mechanical properties of injection-molded blends is insignificant. Nevertheless, the introduction of even a minor amount of long-chain branched polypropylene to linear polypropylene leads to a quite significant improvement in final properties.

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