Preparation of a Ceramifiable Phenolic Foam and Its Ceramization Behavior

Kaihong Tang; Yang Yu; Guiqiu Xu; Xiaojun Tang; Ailing Zhang; Tiejun Ge; Yongjiang Li

doi:10.3390/polym14081591

Preparation of a Ceramifiable Phenolic Foam and Its Ceramization Behavior

Polymers (Basel). 2022 Apr 14;14(8):1591. doi: 10.3390/polym14081591.

Authors

Kaihong Tang^{1

2}, Yang Yu^{2

3}, Guiqiu Xu^{2

3}, Xiaojun Tang^{2

3}, Ailing Zhang¹, Tiejun Ge^{2

3}, Yongjiang Li¹

Affiliations

¹ Key Laboratory of Polymer and Catalyst Synthesis Technology of Liaoning Province, School of Environmental and Chemical Engineering, Shenyang University of Technology, Shenyang 110870, China.
² School of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China.
³ Polymer Material Synthesis and Processing Professional Technology Innovation Center of Liaoning Province, Shenyang University of Chemical Technology, Shenyang 110142, China.

Abstract

Ceramifiable phenolic foam (GC-PF) with a low ceramization temperature has been prepared by incorporation of low melting point glass frits (LMG) containing B₂O₃ and Na₂O as main components into a phenolic resin matrix. Fourier transform infrared spectrometry, X-ray diffractometry, and scanning electron microscopy were used for assessment of the structure, phase composition, and morphology of GC-PF before and after combustion analysis, respectively. A glassy ceramic protective layer is formed when GC-PF is exposed to flame or a high temperature environment. The presence of LMG not only reduces the level of defects in the phenolic foam cell wall (gas escape pore), but also promotes the generation of a glassy ceramic protective layer that could inhibit heat feedback from the combustion zone and reduce the rate of formation of volatile fuel fragments. Thermogravimetric analysis and differential scanning calorimetry were used to establish that GC-PF exhibits excellent thermal stability. Limiting oxygen index (LOI) determination suggests that GC-PF displays good flame retardancy. The LOI of GC-PF was as high as 45.6%, and the char residue at 900 °C was six times greater than that for ordinary phenolic foam (O-PF). The area of the raw material matrix of GC-PF after combustion for 60 s was about 1.7 times larger than that for O-PF. A possible mode of formation of glassy ceramics has been proposed.

Keywords: ceramization; flame retardancy; low melting point glass frits; phenolic foam; thermal stability.