The influence of matrix viscosity on the dispersion of nanoclay in polypropylene by melt-mixing

Abstract : The preparation of polypropylene (PP)-organoclay based nanocomposites by melt mixing in twin-screw extrusion is investigated. The purpose is to optimize the dispersion of the organoclay in the PP matrix in order to obtain a final product with enhanced mechanical properties (stiffness, impact…). A compatibilizer, polypropylene grafted with maleic anhydride (PP-g-MA), was used in order to improve the chemical affinity between PP and the organoclay. The nanocomposite formulation was: 85 wt% PP / 10 wt% PP-g-MA / 5wt% organoclay. The influence of screw speed, barrel temperature and matrix viscosity was studied. Dead-stop experiments have been performed, allowing to collect samples all along the screws. The samples were analyzed through scanning electron microscopy, X-Ray diffraction and rheology in small amplitude oscillatory shear. These different techniques allow us to characterize the dispersion state of the organoclay at different scales. The results show that screw speed has a strong impact on the clay exfoliation but is limited by matrix degradation. This degradation is hardly reduced when decreasing barrel temperature and is enhanced with a more viscous matrix. It also appears that intercalation and exfoliation develop early along the screw profile. Depending on the processing conditions, the final dispersion state can be obtained within the first mixing zones and is no more improved afterwards.
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https://hal-mines-paristech.archives-ouvertes.fr/hal-01502233
Contributeur : Nadine Alziary - Manuel <>
Soumis le : vendredi 7 avril 2017 - 14:36:32
Dernière modification le : lundi 12 novembre 2018 - 10:58:59

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  • HAL Id : hal-01502233, version 1

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Guillaume Normand, Edith Peuvrel-Disdier, Bruno Vergnes. The influence of matrix viscosity on the dispersion of nanoclay in polypropylene by melt-mixing. International workshop on "Structure and dynamics of polymer nanocomposites", Jun 2015, Montpellier, France. ⟨hal-01502233⟩

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