•Current advances of fire retardancy of polybutylene succinate (PBS) are reviewed.•Strategies for flame retarding PBS are detailed.•Flame retardant properties and mechanisms of PBS composites are ...commented.•Outlooks of the flame retardant PBS are provided.
Owing to the strong public concerns about environmental protection and potential energy crisis (fossil fuels), there is a global trend of substitution of petrochemical-based polymers towards biopolymers. Polybutylene succinate (PBS), as an emerging biobased and biodegradable polymer, has drawn a great deal of interest in a number of fields. However, high flammability of PBS constitutes a major obstacle for its potential application. In this study, based on the available literature, the approaches used for the flame retardancy of PBS are systematically reviewed. Those approaches include inorganic (nano)particles, lignin, and intumescent flame retardant systems. This comprehensive review aims to outline the recent research advances in the field of flame retardancy of PBS, focusing on the preparation, properties, and mechanisms. Finally, a brief summary and perspective in flame retarding PBS is also given, which may be able to inspire the development of future research and application.
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The paper reviews the different methods for flame retarding polylactide (PLA). They are critically discussed based on the open and patent literature. No real specific methods have been developed for ...PLA but some approaches provide high performance and especially intumescence. The mechanisms of action remain similar to those observed in other polymers.
Polylactide (PLA) is expected to substitute many common thermoplastics for durable applications where flame retardancy is an issue. The paper is the first critical review on this aspect.
•An intumescent system based on melamine poly(aluminum phosphate) and ethylenediamine phosphate.•Combination of the intumescent system and zinc borate for superior fire performance.•At 10% loading, ...significant reductions of pHRR (−63%), FIGRA (−43%), and MARHE (−48%).
A new strategy was developed for the fabrication of intumescent flame retardant system to improve the fire performance of polybutylene succinate (PBS) based on the synergistic effect of ethylenediamine phosphate (EDAP) and melamine poly(aluminum phosphate) (MPAlP) as well as zinc borate (ZnB). Cone calorimetry results exhibited that, with only 10 wt.% total loading of additives, the peak heat release rate (pHRR) and total heat release (THR) of PBS/EDAP&MPAlP(7:3, 8%)/ZnB(2%) were significantly reduced by 63% and 13%, respectively, in comparison to PBS. Meanwhile, the fire growth rate index (FIGRA) and maximum average rate of heat emission (MARHE) were decreased by 43% and 48% respectively, and its flameout time reached up to 840 s from 493 s for neat PBS. It should be noted that solid-state MAS NMR (11B, 13C, 27Al, and 31P) technique provided information to determine chemistry in the condensed phase during combustion. It was evidenced that the combination of EDAP/MPAlP and ZnB led to the formation of a protective intumescent char embedded with highly thermally stable phosphate species (e.g., boron phosphate and zinc phosphate). They improved the cohesion (crack-free) and stability as well as the resistance of the char, thus improving the fire retardancy of PBS. Additionally, PBS/EDAP&MPAlP(7:3,8%)/ZnB(2%) showed low smoke emission and good thermal/mechanical properties, thanks to the introduction of zinc borate. As a result, this work provides a new perspective for the development of new intumescent flame retardant systems toward PBS.
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High performance and high temperature polymers are a class of polymeric materials exhibiting high thermal stability and their resistance to fire makes them valuable assets for many applications. ...Those applications include as typical examples high temperature gas separation membranes, automotive and aerospace industry as well as the construction industry. The high performance polymers have been synthesized since the early 1960s, and have developed rapidly over the past few decades. Most high performance polymers comprise a highly aromatic backbone, linear chains, and strong inter-chain interactions. This review deals mostly with commercial polymeric materials. Studies regarding their thermal behavior, degradation mechanism and their reaction to fire have been synthetically combined in order to bring out potential insight concerning the effect of the thermal decomposition and thermal behavior on the fire properties of those polymers.
•Ethylenediamine phosphate (EDAP) was used to flame retard polybutylene succinate (PBS).•Effect of different co-additives on the flame retardancy of PBS/EDAP was investigated.•Combination of EDAP and ...ZnB reduces the pHRR, FIGRA, and MARHE of PBS by 57%, 47%, and 48%, respectively, with 10% loading.
In this work, a series of intumescent flame retarded polybutylene succinate (PBS) formulations have been developed based on ethylenediamine phosphate (EDAP) and different co-additives, i.e., zinc borate, melamine borate, zinc molybdate, and aminated multiwall carbon nanotubes, at relatively low loading (10 wt.%). Among them, zinc borate endows the best synergistic flame retardant effect with EDAP in PBS. Cone calorimetry shows that addition of EDAP and zinc borate with a ratio of 8:2 (wt: wt) dramatically reduces the peak heat release rate (pHRR) by 57% as compared to neat PBS, indicating the excellent flame retardant efficiency of this combination used at only 10wt.%. Beside, benefitting from the incorporation of zinc borate, PBS/EDAP/ZnB exhibits excellent smoke suppression and good mechanical properties. Solid state NMR (11B, 13C, and 31P) gives information to determine the flame retardant mechanism of EDAP and ZnB in PBS. It was found that it involves the formation of a reinforced intumescent char with highly thermally stable inorganic species, which acts as a protective physical barrier increasing the char cohesion and limiting the formation of cracks.
-Novel intumescent polybutylene succinate containing low loading of fire retardants.-Full characterization of the fire retardancy mechanism using advanced techniques, i.e. solid state NMR.-Full ...understanding of the synergistic aspects.
Inspired by the concept of intumescence, this research proposed and exemplified a strategy for reinforcing the carbonaceous structures to improve the fire retardancy of intumescent polybutylene succinate (PBS). Herein, intumescent PBS formulations were fabricated by incorporating ethylenediamine phosphate (EDAP) and melamine (MEL) or melamine cyanurate (MCA) as well as zinc borate (ZnB) into PBS at a relatively low loading (10 wt%). The reaction to fire of PBS formulations were assessed by mass loss calorimeter (MLC) and the reinforcement mechanism of the condensed phase was investigated by solid-state NMR technique. Compared to PBS/EDAP&MEL(5:1,10%) and PBS/EDAP&MCA(5:1,10%), the synergistic combination of ZnB and EDAP&MEL (or EDAP&MCA) significantly reduced the peak of heat release rate (pHRR) of PBS/EDAP&MEL(5:1,8%)/ZnB(2%) and PBS/EDAP&MCA (5:1,8%)/ZnB(2%) by 61% and 53%, respectively, exhibiting high degrees of intumescence. Meanwhile, the fire growth rate index (FIGRA) were reduced by 48.8% and 39.5%, respectively, and the maximum average rate of heat emission (MARHE) decreased by 47.9% and 53.3%, respectively. Moreover, the flameout time increased by 428 s (from 507 to 935 s) and 444 s (from 509 to 954 s), respectively. Those phenomena suggested a synergistic flame retardant effect of ZnB and intumescent additives on PBS. Solid-state NMR of 11B, 13C and 31P of the top and bottom of chars after MLC test demonstrated the strengthening of the protective char by the formation of borophosphate and other phosphate glasses, limiting cracking and increasing the char cohesion.
In this work, a series of multi‐component intumescent PBS formulations were elaborated by the combination of intumescent flame retardant (IFR) system (consisting of ethylenediamine phosphate and ...melamine poly(aluminum phosphate), 7:3, wt:wt) and synergists. Three boron/zinc‐containing compounds (i.e., melamine borate, zinc oxide, zinc carbonate) were examined as potential synergists to improve the fire behavior and fire retardancy of PBS. The MLC results showed that the incorporation of all of these compounds enhanced the fire retardancy of PBS to some extent. Among them, zinc oxide exhibited the best fire retardant performances in terms of reduction of the peak heat release rate (pHRR, −61%), fire growth rate index (FIGRA, −19%), maximum average rate of heat emission (MARHE, −55%), and increase of the time to pHRR (+370 s) and to flameout (+650 s) as compared to PBS/IFR10%. Furthermore, the effect of zinc oxide loading on the fire retardancy of PBS was also investigated, the results showed that 2 wt.% loading exhibited the best performances. Solid‐state NMR characterization indicated that the presence of ZnO resulted in the formation of a crack‐free and dense intumescent char layer reinforced by complex aluminum‐zinc‐phosphates glassy species. The intumescent char layer provided a protective physical barrier with improved flexibility and cohesion, which effectively limits the heat and mass transfer between condensed and gas phases and hence, improving the fire retardancy of PBS.
This article reports the thermal and fire behaviors of a high performance polymer, namely polyimide (PI). These behaviors were investigated using different techniques and tests, i.e., ...pyrolysis-Gas-Chromatography/Mass-Spectrometry (py-GC/MS) and TGA coupled with a Fourier Transform InfraRed spectrometer (TGA-FTIR), and mass loss cone (MLC) at different heat fluxes. It was observed that the thermal stability of PI strongly depends on the oxygen concentration. The main identified gases released during thermal degradation are: carbon dioxide, carbon monoxide, water and organic compounds (phenol, aniline, cyanobenzene, dicyanobenzene, 4-aminophenol, benzene, 2-(4-hydroxyphenyl)isoindoline-1,3-dione, phthalimide, dibenzofuran, and diphenylether). The ignition of PI in MLC experiment is observed under an external heat flux of 60 kW/m2. In that case, the peak of heat released by polyimide is only 30 kW/m2. Based on these investigations, a possible decomposition pathway of PI is proposed.
•Polyimide thermal stability is oxygen dependent.•Polyimide ignites at a heat flux superior or equal to 60 kW/m2.•At 60 kW/m2 the peak of heat released by polyimide is only 30 kW/m2.•Polyimide degradation reactions is proposed.
This article deals with the improvement of flame retardancy of polybutylene succinate (PBS) using isosorbide modified by sulfur, silicon or phosphorus as fire retardants (FRs). The syntheses of these ...FRs are detailed, and all molecules were analyzed by liquid state nuclear magnetic resonance (NMR). Prior to be incorporated into PBS, the thermal stability of all flame-retardants was analyzed by thermogravimetric analysis (TGA). The results showed that all FRs exhibit thermal stabilities (>170 °C) suitable for the processing of PBS (140 °C). The fire properties of the PBS formulations were investigated and it was shown that i) sulfur modified FRs showed no improvement of PBS flame retardancy, ii) silicon modified FRs showed slight improvement acting as char forming agent when blending with intumescent FR, iii) performances of phosphorus modified FRs depend on the oxidation degree of phosphorus when evaluated by cone calorimetry, and at UL-94 tests these phosphorus modified FRs achieved V-0 rating with dripping without ignition of the cotton.
•Sulfur, silicon or phosphorus modified isosorbide compounds were successfully synthesized.•The isosorbide based flame-retardants exhibit thermal stability higher than 170 °C.•Formulations based on PBS and phosphorus modified isosorbide achieved V-0 rating at UL-94 test.
A broad spectrum of applications of “Salen”-based Schiff bases tagged them as versatile multifunctional materials. However, their applicability is often bounded by a temperature threshold and, thus, ...they have rarely been used for high temperature applications. Our investigation of a classical Schiff base, N,N′-bis(4-hydroxysalicylidene)ethylenediamine (L2), reveals that it displays an intriguingly combative response to an elevated temperature/fire scenario. L2 resists and regulates thermal degradation by forming an ablative surface, and acts as a thermal shield. A polycondensation via covalent cross-linking, which forms a hyperbranched cross-linked resin is found to constitute the origin of the ablative surface. This is a unique example of a resin formation produced with a Schiff base, that mimicks the operational strategy of a high-heat resistant phenolic resin. Further applicability of L2, as a flame retardant, was tested in an engineering polymer, polyamide-6. It was found that it reinforces the polymer against fire risks by the formation of an intumescent coating. This paves the way for a new strategic avenue in safeguarding polymeric materials toward fire risks. Further, this material represents a promising start for thermal protective applications.
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