Enhancement of flame‐retardant and mechanical performance of phenolic foam with the incorporation of cardanol‐based siloxane

Abstract

A novel cardanol-based siloxane (SAECD), which has silicon groups and reactive epoxy groups, was synthesized. Its structure was confirmed by Fourier transform infrared spectrometry and 1 H nuclear magnetic resonance. Then, phenolic foams (PFs) modified with different contents of SAECD were prepared. While addition of appropriate amount of SAECD into resin matrix enhances the flexural strength of PFs, incorporation of SAECD into PFs leads to a reduced pulverization ratio. The limiting oxygen index (LOI) increases continuously with the increasing addition of SAECD into PFs. The results of the cone calorimeter test showed that the addition of 3% SAECD could effectively reduce the heat release rate and total heat release of the foam by the condensed phase flame retardant mechanism. The TTI of the modified foam was delayed by 19 s; the PHRR, mean HRR, and THR of the modified foams decreased by 9.10%, 4.11%, and 7.55%, respectively, compared with those of the pristine PF. In addition to the increase in the toughness of the PF, SAECD addition can also improve the flame retardant properties of the PF. K E Y W O R D S ORCID Caiying Bo https://orcid.org/0000-0002-7032-9931 F I G U R E 9 Photographs of char residues of PF and 3% SAECD modified PF [Color figure can be viewed at wileyonlinelibrary.com]

Lignin-Based Phenolic Foam Reinforced by Poplar Fiber and Isocyanate-Terminated Polyurethane Prepolymer

“…In addition, PFs also have shortcomings in terms of raw materials and their own characteristics, which restrict their large-scale applications. Due to their expensive petroleum-based raw materials, such as phenol, their cost is relatively high [ 9 , 10 , 11 , 12 ]. Additionally, due to the structural characteristics of phenolic resins, there are many rigid methylene bridge bonds in pure phenolic foams, which make the resulting foam material brittle, which affects their construction applications.…”

Effective Halogen- and Phosphorus-Free Polyphenylene Ether Resin-Based Flame-Retardant Foam

“…To improve its flame retardancy, phosphorus and silicon compounds have been added to PF. Yang et al 15 first synthesized a novel cardanol-based siloxane (SAECD) and modified PFs using different contents of SAECD. The addition of 3% SAECD could effectively reduce the heat release rate (HRR) and total heat release (THR) of the foam through a condensed-phase flame-retardant mechanism.…”

Thermosetting resins from a tetra‐functional vinylbenzene compound possessing cyclic siloxane cores

“…Moreover, the cD 4 structure of polymeric materials might contribute to char formation at high temperatures, resulting in decreases in the formation of volatile and combustible molecules from their thermal degradation. Consequently, the cD 4 structure could contribute to enhance the flame retardancy of the polymeric materials 19–23 . Consideration of the development trends of flame retardants for polymers toward halogen‐ and phosphorus‐free, silicon‐containing compounds could be of potential flame‐retardant agents for the demands 19–23 …”