Polyethylene glycol supported by phosphorylated polyvinyl alcohol/graphene aerogel as a high thermal stability phase change material

Shen, Jieliang; Zhang, Ping; Song, Lixian; Li, Jiapeng; Ji, Bingqiang; Li, Jiajun; Chen, Lin

doi:10.1016/j.compositesb.2019.107545

Cited by 95 publications

(46 citation statements)

References 47 publications

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“…In the literature [18], they tested polystyrene composites with 21.4 wt% ammonium polyphosphate, and found that the peak of the heat release rate was reduced by 77.5% as compared to those of virgin polystyrene. In the literature [19], it was found that the peak heat release rate of PEG could be decreased by 19.2% by introducing graphene aerogels (GA) with 1.60 wt% and phosphorylated polyvinyl alcohol (PPVA) with 15.0 wt%. In the literature [20], it was found that, with 0.25 phr of functionalized graphene oxide (fGO) and 10 phr of EG/dimethyl methyl phosphonate (DMMP), the LOI value of RPUF/fGO composites reached 28.1%, and its UL-94 test reached V-0 rating, showing that the fGO could significantly enhance the flame retardant properties of RPUF composites.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Environmentally Friendly Flame Retardants on the Thermal Stability of Phase Change Polyurethane Foams

Liu

2020

Materials

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To improve thermal insulation, microencapsulated phase change materials (micro-PCMs), expandable graphite (EG), and ammonium polyphosphate (APP) were introduced into polyurethane foam (PUF) to enhance the thermal stability and improve the thermal insulation behavior. The morphology of the PUF and micro-PCM was studied using a scanning electronic microscope (SEM), while the thermophysical properties of the PUF were investigated using a hot disk thermal constants analyzer and differential scanning calorimetry (DSC). The thermal stability of the PUF was investigated by thermogravimetric analysis (TGA), and the gas products volatilized from the PUF were analyzed by thermogravimetric analysis coupled with Fourier transform infrared spectrometry (TGA-FTIR). The results revealed that the thermal conductivities of the PUF were reduced because micro-PCM is effective in absorbing energy, showing that the PUF functions not only as a thermal insulation material but also as a heat sink for energy absorption. Moreover, the EG and APP were found to be effective in improving the thermal stabilities of the PUF, and the optimized formulation among EG, APP, and micro-PCMs in the PUF showed a significant synergistic effect.

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Section: Introductionmentioning

confidence: 99%

The Influence of Environmentally Friendly Flame Retardants on the Thermal Stability of Phase Change Polyurethane Foams

Liu

2020

Materials

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“…Figure presents Raman spectra of char residues for PP‐5 and PP‐7. It is noted that each spectrum has two visible bands (D and G bands), and peak area ratio of the two bands ( I D / I G ) is an indicator for graphitization degree of carbon materials . The I D / I G values of PP‐5 and PP‐7 samples are 2.33 and 2.73, respectively, which indicates that graphitization degree of PP‐5 char is higher.…”

Section: Resultsmentioning

confidence: 99%

Supramolecular self‐assembly modification of ammonium polyphosphate and its flame retardant application in polypropylene

Yuan

Dong

et al. 2020

Polymers for Advanced Techs

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In order to improve its water resistance and compatibility with polymer matrix, ammonium polyphosphate (APP) is modified with melamine-trimesic acid (MEL-TA) aggregates by supramolecular self-assembly technology. Chemical structure and morphology of APP@MEL-TA are investigated by Fourier transform infrared spectroscopy and scanning electron microscopy (SEM), respectively. Intumescent flame retardant system of APP@MEL-TA and charring-foaming agent is introduced into polypropylene (PP) matrix. The flammability and combustion behavior of PP composites are investigated by limiting oxygen index (LOI), UL-94 vertical burning, and cone calorimetry tests. In terms of LOI values and cone combustion results, APP@MEL-TA performs better than pristine APP. Char residue of PP composites is investigated by SEM and Raman spectra. Flame retardant mechanisms are proposed based on thermal decomposition, combustion results, and analysis on char residue. K E Y W O R D S ammonium polyphosphate, flame retardant, polypropylene, supramolecular self-assembly, thermal stability 1 | INTRODUCTION Polypropylene (PP) is widely applied in a variety of applications, such as transportation, cables, housing, and electric industry. However, PP burns very rapidly with the release of a great deal of heat, which limits its applications in many fields. Thus, the improvement in flame retardant properties of PP has become an important research. Zhang et al 1 reviewed the research progress of halogen-containing flame-retarded PP. The obvious disadvantages of traditional halogen-based flame retardants are high fire toxicity and releasing of smoke during the combustion. 2 In addition, environment amity is the theme of whole society, and some halogen-containing flame retardants are undoubtedly damaging the environment. 3-6 Recently, halogen-containing flame retardants have been replaced by halogen-free counterparts, 7-9 which are characterized by their low fire toxicity. Intumescent flame retardants (IFRs) are the most popular halogen-free retardants because of their advantages of low smoke and toxicity during combustion. 10,11 Wang et al 12 prepared a novel IFR by the reaction of melamine (MEL) with methyl hydrogen siloxane, and this flame retardant system can effectively improve flame retardancy of PP.Acid catalyst, blowing source, and charring agent are three main ingredients for IFR system. 13,14 According to its elemental composition, ammonium polyphosphate (APP) acts as acid catalyst and blowing source because of its high phosphorus and nitrogen contents, both of which are primary flame retardant elements. 15,16 However, as an important component of IFR, APP has obvious disadvantages of weak water resistance and poor compatibility with polymer matrix. 3,17,18 Hence, it is of great significance to modify the surface of APP and improve flame retardant properties of resulting composites. In view of these deficiencies, many researches on surface modification of APP have been carried out. The surface characteristics of APP are modified by other flame retard...

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“…Char layer with higher graphitization degree can more effectively protect PP matrix from combustion, leading to the improvement in flame‐retardant effect . Herein, graphitization degree of carbonaceous char is assessed by I D /I G value, which is obtained from the area ratio of D and G bands . As shown in Figure , the I D /I G value of PP/IFR‐2 is lowest.…”

Section: Resultsmentioning

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

Polymers for Advanced Techs

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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,

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Polyethylene glycol supported by phosphorylated polyvinyl alcohol/graphene aerogel as a high thermal stability phase change material

Cited by 95 publications

References 47 publications

The Influence of Environmentally Friendly Flame Retardants on the Thermal Stability of Phase Change Polyurethane Foams

The Influence of Environmentally Friendly Flame Retardants on the Thermal Stability of Phase Change Polyurethane Foams

Supramolecular self‐assembly modification of ammonium polyphosphate and its flame retardant application in polypropylene

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

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