Melt-Mixed Thermoplastic Nanocomposite Containing Carbon Nanotubes and Titanium Dioxide for Flame Retardancy Applications

M. Pérez-Alvarez,P. Reyes-Rodríguez,Z.V. Quiñones-Jurado,G. Cadenas-Pliego,V.J. Cruz-Delgado,M. Andrade-Guel,C. Cabello-Alvarado,C.A. Ávila-Orta,L. Melo-López

doi:10.3390/polym11071204

M. Pérez-Alvarez, P. Reyes-Rodríguez + Show 7 more

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https://doi.org/10.3390/polym11071204

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Abstract

The study of polymeric nanocomposites is a possible alternative to conventional flame retardants. The aim of the present work is to investigate the effects of carbon-nanotubes (CNT) and TiO2 nanoparticles (NPs) on the thermo-mechanical, flammability, and electrical properties of polypropylene (PP). In this work, PP-TiO2/CNT nanocomposites were obtained with TiO2/CNT mixtures (ratio 1:2) through the melt extrusion process, with different weight percentage of nanoparticles (1, 5, and 10 wt %). The PP-TiO2/CNT nanocomposites were characterized by DSC, TGA, MFI, FTIR, XRD, and SEM. It was possible to determine that the thermal stability of the PP increases when increasing the content of NPs. A contrary situation is observed in the degree of crystallinity and thermo-oxidative degradation, which decreased with respect to pure PP. The TiO2 NPs undergo coalition and increase their size at a lower viscosity of the nanocomposite (1 and 5 wt %). The mechanical properties decreased slightly, however, the Young’s modulus presented an improvement of 10% as well as electrical conductivity, this behavior was noted in nanocomposites of 10 wt % of NPs. Flammability properties were measured with a cone calorimeter, and a reduction in the peak heat release rate was observed in nanocomposites with contents of nanoparticles of 5 and 10 wt %

Highlights

Avoiding or preventing fires helps decrease injuries or human losses in automotive industry [1].Different causes arise for these types of events, such as mechanical problems, electrical failures, or car accidents, since most automotive liquids are flammable
Flammability properties were measured with a cone calorimeter, and a reduction in the peak heat release rate was observed in nanocomposites with contents of nanoparticles of 5 and Keywords: nanocomposite; polypropylene; carbon nanotube; titanium dioxide
One of the most common polymers used to obtain polymeric nanocomposites is polypropylene (PP), which is a semi-crystalline thermoplastic widely used in applications such as textile, films, bottles production, and piping, and is the most used in the automotive industry [7,8,9]

Summary

Introduction

Avoiding or preventing fires helps decrease injuries or human losses in automotive industry [1].Different causes arise for these types of events, such as mechanical problems, electrical failures, or car accidents, since most automotive liquids are flammable. The automotive parts manufactured with different polymers are flammable and must be protected against fires [2] For these materials, some flame retardants are applied only in the exterior, and some carbonaceous and ceramic films help to improve their flame-retardant effect [3,4,5,6]. PP has some limitations, such as being sensitive to heat and oxidative degradation, as well as its fragility This polymer by itself is prone to crack or vulnerable to mechanical failures and, like most polymers, has low electrical and thermal conductivity; for these reasons, the addition of nanoparticles or nanocharges has been adopted with the purpose of changing properties of neat polymer [10,11]

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