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A facile methodology to effectively improve the melt strength and microcellular foamability of isotactic polypropylene

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Abstract

Melt strength is crucial in foam-processing of polymer materials, especially for linear molecular structured isotactic polypropylene (iPP), which has comparatively weak melt strength to hinder its foaming. In this study, a commercial high melt strength polypropylene (HMSPP) was added into the iPP matrix, cooperated with a thermal treatment, aiming to enhance the melt strength and microcellular foamability of iPP under supercritical CO2. Melt strength enhancement effect was proved by rheological and microcellular foaming results. The crystallization and batch foaming behaviors of iPP and its HMSPP added blends at different foaming conditions were investigated. It was observed that the addition of HMSPP could refine the crystals of the blends, and the crystal nucleation sites could be increased apparently. Cooperated with the suitable thermal control schedule during the batch foaming process, the introduced crystals could correspondingly improve the melt strength and cell nucleating ability of HMSPP added iPP. At a given HMSPP content of 20 wt.%, quite fine microcellular foams with the average cell size of 0.8 μm, and cell density up to 1012 cells/cm3 were fabricated.

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Acknowledgements

The authors sincerely thank the National Natural Science Foundation of China (11872338), and the Henan Province Natural Science Projects of China (18B430016, 192102210024, 19B430011), for their financial supports.

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  1. Long Fu contributed equally to this work.

Authors and Affiliations

  1. School of Materials Science and Engineering, National Engineering Research Center for Advanced Polymer Processing Technology, Zhengzhou University, Zhengzhou, 450001, China

    Qiankun Shi, Long Fu, Yang Yang, Kun Li, Baochen Liu, Xiaoli Zhang & Jingbo Chen

  2. National Local Joint Engineering Laboratory of Intelligent Manufacturing Oriented Automobile Die & Mold, Tianjin University of Technology and Education, Tianjin, 300222, China

    Quan Wang

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  1. Qiankun Shi
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Correspondence to Xiaoli Zhang.

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Shi, Q., Fu, L., Yang, Y. et al. A facile methodology to effectively improve the melt strength and microcellular foamability of isotactic polypropylene. J Polym Res 27, 118 (2020). https://doi.org/10.1007/s10965-020-02101-9

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