Synthesis and surface modification of nanophosphorous-based flame retardant agent by continuous flow hydrothermal synthesis--颗粒学报PARTICUOLOGY

Elbasuney, S., & Mostafa, H. E. (2015). Synthesis and surface modification of nanophosphorous-based flame retardant agent by continuous flow hydrothermal synthesis. Particuology, 22, 82-88. https://doi.org/10.1016/j.partic.2014.10.005

Synthesis and surface modification of nanophosphorous-based flame retardant agent by continuous flow hydrothermal synthesis

Sherif Elbasuney ^*, Hosam E. Mostafa

School of Chemical Engineering, Military Technical College, Kobry El-Koba, Cairo, Egypt

10.1016/j.partic.2014.10.005

Volume 22, October 2015, Pages 82-88

Received 27 July 2014, Revised 28 September 2014, Accepted 2 October 2014, Available online 28 January 2015, Version of Record 4 August 2015.

E-mail: sherif_basuney2000@yahoo.com

Highlights

• Surface-modified Ca₅(OH)(PO₄)₃ (HA) nanoparticles were prepared via continuous hydrothermal method.

• A self extinguishing multicomponent epoxy nanocomposite was synthesized at a solid load <10 wt%.

• Synergism between solid loading of HA retardant and a conventional intumescent was investigated.

Abstract

Nanoparticles can provide flame retardance to hosting polymers and act as nano fire extinguishers. Hydroxyapatite (Ca₅(OH)(PO₄)₃) (HA) is not hygroscopic, and is thermally stable up to 800 °C, with 18.5 wt% phosphorous content. It is this high phosphorous content that can provide HA with flame retardant properties. In this paper, we report on the continuous synthesis of ultrafine HA using a hydrothermal synthesis technique. The HA surface properties were changed from hydrophilic to hydrophobic by post-synthesis surface modification. The ratio of the HA nanoparticles and an intumescent agent known as Exolit AP750 was investigated to yield a self-extinguishing multi-component epoxy nanocomposite for extended application under extreme fire conditions. The HA/AP750/epoxy nanocomposite was able to resist a flame at 1700 °C and self-extinguish after the flame had been removed. The nanocomposite showed an enhanced flammability performance in standard cone calorimetry testing and formed a compact and cohesive protective char layer with a 50% decrease in peak heat released compared with virgin epoxy. Our aim was to establish the use of HA as an effective nanofiller with phosphorous-based flame retardant properties. The surface of this nano fire extinguisher was modified effectively with different surfactants for enhanced compatibility with different polymeric matrices.

Graphical abstract

Keywords

Flame retardancy; Phosphorous-based agent; Nanocomposites; Hydrothermal synthesis; Hydroxyapatite

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