Synthesis of K-Carrageenan Flame-Retardant Microspheres and Its Application for Waterborne Epoxy Resin with Functionalized Graphene

Abstract

In this article, the intumescent flame-retardant microsphere (KC-IFR) was prepared by inverse emulsion polymerizations, with the use of k-carrageenan (KC) as carbon source, ammonium polyphosphate (APP) as acid source, and melamine (MEL) as gas source. Meanwhile, benzoic acid functionalized graphene (BFG) was synthetized as a synergist. A “four-source flame-retardant system” (KC-IFR/BFG) was constructed with KC-IFR and BFG. KC-IFR/BFG was blended with waterborne epoxy resin (EP) to prepare flame-retardant coatings. The effects of different ratios of KC-IFR and BFG on the flame-retardant properties of EP were investigated. The results showed that the limiting oxygen index (LOI) values increased from 19.7% for the waterborne epoxy resin to 28.7% for the EP1 with 20 wt% KC-IFR. The addition of BFG further improved the LOI values of the composites. The LOI value reached 29.8% for the EP5 sample with 18 wt% KC-IFR and 2 wt% BFG and meanwhile, UL-94 test reached the V-0 level. In addition, the peak heat release (pHRR) and smoke release rate (SPR) of EP5 decreased by 63.5% and 65.4% comparing with EP0, respectively. This indicated the good flame-retardant and smoke suppression property of EP composites coating.

Effects of a Macromolecule Spirocyclic Inflatable Flame Retardant on the Thermal and Flame Retardant Properties of Epoxy Resin

“…Nuclear magnetic resonance (NMR) spectroscopy: 1 H-NMR, 13 C-NMR and 31 P-NMR spectra were recorded on an FT-80A NMR spectrometer (VARIAN, Palo Alto, CA, USA). (Methyl sulfoxide)-d6 (DMSO-d6) was used as the solvent, and the solution was measured with tetramethyl silane (TMS) and phosphoric acid as internal standards.…”

“…However, the intumescent flame retardant (IFR) is considered to be an important way to make the flame retardant process halogen-free and green [11]. Since the 2 of 16 1990s, the flame retardant mechanism of IFRs has been continuously updated, and modified IFR systems have also emerged [12,13].…”

“…1 H NMR (a),31 P NMR (b) and13 C NMR (c) spectra of SPDPC; 1 H NMR (d),31 P NMR (e) and13 C NMR (f) spectra of SAPC.Polymers 2020, 12, x FOR PEER REVIEW 6 of 16…”

Modified Epoxy Resin Synthesis from Phosphorus—Containing Polyol and Physical Changes Studies in the Synthesized Products

“…The epoxy composition comprised an epoxy resin and amine or anhydride curer combined to form epoxy three-dimensional polymers useful for these applications. While several studies have focused on improving the mechanical properties of epoxy resins by modifying them or adding tougheners in epoxy compositions [7][8][9][10], the increase of thermal stability related to flame retardant (FR) is an increasing demand in automobiles, aircrafts, or flip-chip encapsulation [11][12][13].…”

“…Traditionally, inorganic additives are often used to improve thermal stability such as aluminum hydroxide, magnesium hydroxide, or ammonium polyphosphate (APP). However, for a few applications such as those involving the resin transfer molding system, the modification of epoxy resins is preferred for the uniform distribution of the resin in the composites [12]. An example of a high thermal stability of resin is tetrabromobisphenol A epoxy resin (TBBPA).…”