Preparation of Poly(phosphoric acid piperazine) and Its Application as an Effective Flame Retardant for Epoxy Resin

ZHS@ Mg‐Al‐LDH and ZHS@α‐ZrP hybrid materials were prepared by electrostatically loading zinc hydroxystannate (ZHS) on the layered compounds (Mg‐Al‐LDH and α‐ZrP) in this work. With the addition of 2 wt% of the two hybrid materials to epoxy resin (EP), respectively, the fire hazard of EP and its composites were investigated. The limiting oxygen index (LOI) of ZHS@ Mg‐Al‐LDH/EP composite increased by 19.0% compared with pure EP, while its peak heat release rate (PHRR), total heat release rate (THR), and peak smoke release rate (SPR) decreased by 48.2%, 20.8%, and 21.6%, respectively, evidenced by the results of the LOI test and cone calorimetry test (CCT). The LOI of ZHS@α‐ZrP/EP composite increased by 20.4%, and its PHRR, THR, and SPR decreased by 47.7%, 21.4%, and 27.1%, respectively. Both hybrid materials showed prominent flame retardant and smoke suppressing properties. In addition, through the analysis of the TG‐IR and Raman spectrum of residual char, the specific mechanism of flame retardance and smoke suppression was explored.

Section: Resultsmentioning

confidence: 99%

“…Figure 10A , and hydrocarbon (3100-2800 cm −1 ). 24,25 It can be found that the characteristic peaks of Figure 10A,B,C are similar, indicating that EP and its composites have similar gaseous pyrolysis products. In addition, it is observable that the EP composite has significant gas product evolution at 34 minutes.…”

Section: Tg-ir Analysismentioning

confidence: 85%

Effect of different ionic layered compounds decorated with zinc hydroxystannate on flame retardancy and smoke performance of epoxy resin

Wang

et al. 2019

“…The addition of a flame retardant to a polymer is an effective method to improving its flame retardancy. Li et al successfully synthesized a polyphosphoric acid piperazine flame retardant (PPAP) containing nitrogen and phosphorus using polyphosphoric acid and piperazine and used it as an additive for flame‐retardant EP resin thermosets. The obtained PPAP showed high flame‐retardant efficiency in the case of the EP matrix.…”

Section: Introductionmentioning

confidence: 99%

Activated carbon spheres (ACS)@SnO₂@NiO with a 3D nanospherical structure and its synergistic effect with AHP on improving the flame retardancy of epoxy resin

Líu

et al. 2019

A novel activated carbon spheres (ACS)@SnO2@NiO hierarchical hybrid architecture was first synthesized and applied for enhancing the flame retardancy of epoxy (EP) resin via a cooperative effect. Herein, using activated carbon microspheres as the template, SnO2 and NiO nanospheres were successively anchored to it by a sedimentation‐calcination strategy. The well‐designed ACS@SnO2@NiO significantly enhanced the flame retardancy for consistency of EP composites, as demonstrated by thermogravimetric and cone calorimeter experiments. For instance, the incorporation of 2 wt% ACS@SnO2@NiO decreased by 15.5% maximum in the total smoke production, accompanying the higher graphitized char layer. In addition, the synergetic mechanism of flame retardancy between ACS@SnO2@NiO and aluminum hypophosphite (AHP) was investigated. The obtained sample satisfied the UL‐94 V‐0 rating with a 5.0 wt% addition of AHP and ACS@SnO2@NiO (the ratio of the mass fraction of AHP to ACS@SnO2@NiO is 4.5:0.5). Notably, the incorporation of AHP and ACS@SnO2@NiO resulted in a significant decrease in the fire hazard properties of EP resin; for instance, 4.5AHP‐0.5ACS@SnO2@NiO/EP resulted in a maximum decrease of 32.4% in the total smoke production as compared with that of pure EP resin. It should be noted that the improved flame‐retardant performance for the EP composites is primarily attributed to the synergistic effect of ACS@SnO2@NiO and AHP in promoting the formation of residual char in the condensed phase.

“…Melamine cyanurate (MCA), a commercial flame retardant with planar network, is synthesized through hydrogen bonding supramolecular self‐assembly of melamine and cyanuric acid (CA) . PA is a kind of heterocyclic compound containing two nitrogen atoms, which shows an obvious flame‐retarding effect for its good thermostability, high nitrogen content, and high reactivity . For instance, PA was used to synthesize a P‐N flame retardant via its amidation reaction with diphenylphosphinyl chloride, and the results indicated that both thermostability and water tolerance of the resultant PP composite are promoted .…”

Section: Introductionmentioning

confidence: 99%

Preparation of piperazine cyanurate by hydrogen‐bonding self‐assembly reaction and its application in intumescent flame‐retardant polypropylene composites

Dong

Yuan

et al. 2019

Piperazine cyanurate (PCA) is designed and synthesized via hydrogen-bonding selfassembly reactions between piperazine and cyanuric acid. Chemical structure and morphology of PCA are investigated by Fourier transform infrared spectroscopy and scanning electron microscopy, respectively. The prepared PCA is combined with ammonium polyphosphate (APP) to prepare flame-retardant polypropylene (PP) composites. Thermostability, flammability, and combustion characteristics of PP composites are analyzed. The maximum thermal decomposition rate of flameretarded PP composites has an apparent reduction compared with that of pure PP, and obvious char is left for this intumescent flame retardant (IFR) system of APP and PCA. A high limiting oxygen index value and UL-94 V-0 rating are achieved with addition of APP and PCA. In cone calorimetry test, heat and smoke releases of PP are significantly decreased by this IFR system. Gaseous decomposition products during the thermal decomposition of flame-retardant composites are studied. Chemical structure and morphology of char residues are analyzed. The results illustrate that APP and PCA have a superb synergistic action in the aspect of improvement in fire safety of PP. A possible flame-retardant mechanism is concluded to reveal the synergism between APP and PCA. K E Y W O R D S intumescent flame retardant, mechanism, polypropylene, synergism 1 | INTRODUCTION Polymeric materials, which are now universally used in many areas, have been important to modern life for many years. Polypropylene (PP) is one of the universal polymers and has many advantages, such as easy processability, corrosion resistance, and low cost. However, it is a kind of easily combustible material, which seriously restricts its applications. Because of its emission of poisonous gases while burning, PP has high fire hazard potential for human life. 1,2 Therefore, PP materials must be modified with flame-retardant additives in order to achieve desired flame-retardant performance and meet the requirements in some application fields. Currently, considerable effort has been devoted to explore methods of reducing the inflammability of PP. Various flame retardants, such as metallic hydroxide, expandable graphite, halogencontaining flame retardants, and phosphorous-containing compounds, have been successfully developed to endow PP with flame retardancy. 3 For instance, metal hydroxides, including aluminum hydroxide and magnesium hydroxide, are used in PP, but mechanical properties of PP materials are easily destroyed by high loading of fillers. 4 As a kind of halogen flame retardants, bromine-containing compound has been regarded as the most effective flame retardant for PP. 5 However, some halogen-containing flame retardants are being phased out because of their health and environmental hazards,