Covalently-functionalized graphene oxide via introduction of bifunctional phosphorus-containing molecules as an effective flame retardant for polystyrene

Abstract

Covalently-functionalized graphene oxide (FGO) was successfully prepared by grafting a novel phosphorus-containing flame retardant, [2-((6-oxidodibenzo[c,e][1,2]oxaphosphinin-6-yl)methoxy) acryloxyethylchlorophosphate, PACP], to graphene oxide (GO). The resulting FGO demonstrated hydrophobicity and stability in polar solvents such as N,N-dimethylformamide (DMF). The reactive vinyl groups of PACP attached to FGO further copolymerized with styrene to produce polystyrene-FGO (PS-FGO) nanocomposites. PS-FGO samples showed obviously improved fire-resistance, thermal behavior and glass transition temperature in comparison with those of neat PS and PS-GO samples, due to the good dispersion of FGO in PS as well as the strong interfacial bonds between FGO and the matrix. In addition, thermogravimetry-Fourier transform infrared (TG-FTIR) results indicated that the evolution of volatile products from PS decomposition was significantly inhibited by the introduction of FGO.Furthermore, scanning electron microscopy (SEM) and FTIR and Raman spectroscopy were employed to investigate the char residue, elaborating the flame-retardance mechanism.Scheme 1 Synthesis route of DOPO-OH.Scheme 2 Synthesis routes of (a) FGO and (b) PS-FGO nanocomposites.

A study on preparation of modified Graphene Oxide and flame retardancy of polystyrene composite microspheres

“…We can see that in pure PS microspheres, the HRC can be as high as 1000 J/g·k −1 . With the increase of GO-ODOPM, the HRC value decreased from 1000 J/g·k −1 (PS) to 645 J/g·k −1 (3 wt% GO-ODOPM/PS), which can be attributed to the decrease of the maximum mass loss rate and the reduction of combustion heat of decomposition products at this temperature [28]. In the GO-ODOPM/PS composite microsphere system, the ODOPM decomposed during combustion to produce phosphorus-containing radicals and polyphosphoric acid.…”

Reactive and Additive Modifications of Styrenic Polymers with Phosphorus-Containing Compounds and Their Effects on Fire Retardance

“…There is a wide range of organic P-containing FRs available including phosphates, phosphonates, polyphosphonates, hybrid metal phosphonate salts, etc. [ 5 , 38 , 41 , 109 , 110 , 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 ]. The mechanism and the efficiency of FRs depend not only on the chemical structure of a P-bearing compound itself, but also on its interaction with the polymeric backbone during pyrolysis and combustion.…”

“…The use of graphene oxide (GO) as a FR additive was already discussed in this review earlier [ 50 , 82 , 83 ]. Recently, Dai et al (2018) covalently functionalised GO with a novel organic P-containing compound, 2-((6-oxidodibenzo[c,e][1,2]oxaphosphinin-6-yl)methoxy)acryloxyethyl)chlorophosphate (PACP), the structure of which is shown in Figure 27 b [ 123 ]. From 1 to 3 wt% of the FGO were incorporated into the PS chain via the bulk polymerisation method, using benzoyl peroxide as the initiator and heating the reaction mixture to 90 °C.…”

“…From 1 to 3 wt% of the FGO were incorporated into the PS chain via the bulk polymerisation method, using benzoyl peroxide as the initiator and heating the reaction mixture to 90 °C. The good dispersion of the FGO within the polymer and the strong interfacial bonds between the FGO and the polymer matrix resulted in the significant improvement of thermal behaviour and fire resistance [ 123 ]. The TG char residue of the copolymer with 3 wt% of reactive FR increased from 0.33 to 6.50 wt% under the inert atmosphere.…”

Flame Retardation of Natural Rubber: Strategy and Recent Progress

“…Moreover, nano flame retardants are superior to almost all current flame retardants in terms of improving the physical properties of polymer substrates. Since montmorillonite (MMT) nanoparticles were used to fabricate a flame-retarding PA6 nanocomposite by Toyota Corporation (Japan) in 1976, more and more nano flame retardants have been introduced to prepare high-performance flame-retarding polymers [73], such as graphite oxide (GO) [74,75], layered doubled hydroxides (LDH) [76], carbon nanotubes (CNTs) [77], polyhedral oligosilsesquioxane (POSS) [78], fullerene (C60) [79], etc. The flame-retardant mechanisms of nano flame retardants are very complicated, in which the interaction between nano flame retardant and substrate is the critical factor, thus, the flame-retardant mechanism for different nano flame retardants in different polymers may be different due to various structural features of the polymer matrix and nanoparticles.…”