A novel ceramifiable epoxy composite with enhanced fire resistance and flame retardance
- PDF / 2,747,318 Bytes
- 13 Pages / 595.276 x 790.866 pts Page_size
- 88 Downloads / 167 Views
A novel ceramifiable epoxy composite with enhanced fire resistance and flame retardance Dong Zhao1,2 · Wei Liu1,2 · Yucai Shen1,2 · Tingwei Wang1,3 Received: 8 January 2020 / Accepted: 19 August 2020 © Akadémiai Kiadó, Budapest, Hungary 2020
Abstract A novel epoxy composite with flame retardance and fire resistance was prepared by adding silicate glass frit (SGF) and ammonium polyphosphate (APP) into the epoxy resin. In the combustion test, epoxy composites displayed obvious flame retardance feature, showing much lower heat release rate, total heat release and total smoke production than epoxy resin. The composite residue formed at 900 °C had a flexural strength of 19.05 MPa. In addition, possible mechanisms for the phase separation and crystallization reactions at high temperatures were also investigated in detail through thermogravimetric analyzer, X-ray diffraction, X-ray photoelectron spectrometer, and scanning electron microscopy. It was suggested that phosphorus element tends to migrate to the surface of the composite residue during firing process, and sodium element from SGF is selectively combined with the phosphorus element to obtain crystalline phases. With this unique phase separation and crystallization reactions, the fire resistance of the epoxy composite was significantly improved. Graphical abstract
Si
SiO2
O
Cristobalite
Na Na+ P2O5 (From APP)
Peak of heat release rate
SGF
+
High temperature P2O5 + Na+
944.95kW/m2
Na4P2O7
Na4P2O7
19.05MPa
534.91kW/m2 0MPa (No residue)
Epoxy
EPSA
Epoxy.composite
Epoxy
EPSA
Flexural strength of ceramic
+
Ceramic-like residue
Keywords Epoxy · Composites · Ceramifiable · Flame retardance · Fire resistance
Introduction Dong Zhao and Wei Liu have contributed equally to this work. Extended author information available on the last page of the article
Epoxy resin is one of the most versatile thermosetting polymeric materials, which has a wide application in various fields owing to its excellent adhesive properties, satisfactory
13
Vol.:(0123456789)
chemical resistance and good thermal and mechanical stability [1–5]. However, with a limiting oxygen index (LOI) of only 19.5%, epoxy resin is highly flammable, and there is almost no residue left after sufficient combustion, which severely restricts its further application for use as reinforcing material in structural engineering of building [6]. Consequently, it is imperative to improve the flame retardance and fire resistance of epoxy resin. Although a great deal of work [7–11] has been devoted to improving the flame retardancy of epoxy composites through physically adding various flame retardants, it still cannot meet the use requirements in the long-lasting fire or high temperature (over 900 °C) conditions. In order to overcome this problem, strategies to make polymer composite ceramifiable in the fire are reported [12–17], and those ceramifiable composites have similar properties of matrix materials at room temperature, but they could be converted to ceramiclike residues when they are fired
Data Loading...
