Crystallization of linear and branched polypropylene blends with/without nucleating agent

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28110%2F25%3A63593718" target="_blank" >RIV/70883521:28110/25:63593718 - 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

Crystallization of linear and branched polypropylene blends with/without nucleating agent

Original language description

Polypropylene (PP) is one of the most commercially used polymeric materials due to its low cost and good processability. However, commercial PP is commonly prepared using iso-specific Ziegler-Natta or metallocene catalysts, resulting in linear chains and narrow molecular weight distributions, which limits its use in processes where good melt flow properties and melt strength are required, such as thermoforming, film blowing, foaming and fibre spinning. An effective strategy to improve these limiting properties involves the introduction of long chains on the polypropylene backbone. However, this significantly affects crystallization and the resulting morphology. The effect of self-seeding of long chain branched polypropylene (LCB-PP) has been observed, significantly affecting the whole process of crystallization. Thus, the addition of LCB-PP to linear PP could play the role of a nucleating agent (NA) enhancing the crystallization rate and controlling the morphology at the same time. The use of LCB-PP as a nucleating agent also has a great potential in terms of recycling because, unlike commonly used nucleating agents, it is chemically identical to PP.This study compares the effectiveness of a commercially available nucleating agent and different amounts of long chain branched polypropylene acting as a specific α-nucleating agent for linear polypropylene. The sorbitol-based NA, 1,3;2,4-bis(3,4-dimethylbenzylidene)sorbitol (Millad 3988), at a concentration of 0.2 wt. % and LCB-PP at concentrations of 1, 2, 5 and 10 wt. % were immixed into PP. Comparison of the effect of NA and long branches under isothermal conditions on the crystallization kinetics, crystallinity and polymorphic composition was carried out by differential scanning calorimetry and wide-angle X-ray scattering. The addition of LCB-PP, even at the lowest concentration, performs better at higher crystallization temperatures and has a better effect on the crystallization process, crystallization rate and overall crystallization than the addition of NA used.

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

2025

Confidentiality

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