Ultrasound-Assist Extrusion Methods for the Fabrication of Polymer Nanocomposites Based on Polypropylene/Multi-Wall Carbon Nanotubes

Materials

Carlos A. Ávila-Orta¹  Zoe V. Quiñones-Jurado²  Miguel A. Waldo-Mendoza²  Erika A. Rivera-Paz²  Víctor J. Cruz-Delgado¹  José M. Mata-Padilla¹  Pablo González-Morones¹  Ronald F. Ziolo¹ 

[1] Centro de Investigación en Química Aplicada, Blvd. Ingeniero Enrique Reyna Hermosillo. 140, Col. San José de los Cerritos, Saltillo, Coahuila CP 25294, Mexico;Innovación y Desarrollo en Materiales Avanzados A. C., Grupo POLYnnova, Carr. San Luis Potosí-Guadalajara 1510, Nivel 3, Local 12, Lomas del Tecnológico, San Luis Potosí, SLP, CP 78211, Mexico;

关键词: polypropylene;    carbon nanotubes;    melt flow index;    extrusion;    ultrasound;    surface resistivity;    electric charge;   

DOI  :  10.3390/ma8115431

来源: mdpi

【 摘 要 】

Isotactic polypropylenes (iPP) with different melt flow indexes (MFI) were used to fabricate nanocomposites (NCs) with 10 wt % loadings of multi-wall carbon nanotubes (MWCNTs) using ultrasound-assisted extrusion methods to determine their effect on the morphology, melt flow, and electrical properties of the NCs. Three different types of iPPs were used with MFIs of 2.5, 34 and 1200 g/10 min. Four different NC fabrication methods based on melt extrusion were used. In the first method melt extrusion fabrication without ultrasound assistance was used. In the second and third methods, an ultrasound probe attached to a hot chamber located at the exit of the die was used to subject the sample to fixed frequency and variable frequency, respectively. The fourth method is similar to the first method, with the difference being that the carbon nanotubes were treated in a fluidized air-bed with an ultrasound probe before being used in the fabrication of the NCs with no ultrasound assistance during extrusion. The samples were characterized by MFI, Optical microscopy (OM), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), electrical surface resistivity, and electric charge. MFI decreases in all cases with addition of MWCNTs with the largest decrease observed for samples with the highest MFI. The surface resistivity, which ranged from 10¹³ to 10⁵ Ω/sq, and electric charge, were observed to depend on the ultrasound-assisted fabrication method as well as on the melt flow index of the iPP. A relationship between agglomerate size and area ratio with electric charge was found. Several trends in the overall data were identified and are discussed in terms of MFI and the different fabrication methods.

【 授权许可】

CC BY   
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