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In recent years, thermoplastic polyurethane elastomer has shown great application prospects in the fields of polymer film due to its outstanding tensile properties, high elasticity, wear resistance, oil resistance, low temperature resistance, wide range of hardness, and other properties. However, its flammable properties greatly limit its application in the field of polymer film. The self-made GO was used as a carbon source, phenylboronic acid as an acid source, ammonium polyphosphate (APP) as an acid and gas source, and intumescent flame retardant (IFR) was compounded. The IFR was introduced into thermoplastic polyurethane (TPU) to prepare a series of IFR/TPU composite films with different formulations. The results show that PA and GO can make up for the loss of mechanical properties caused by the addition of APP and improve the thermal stability of the composite film, and the IFR flame retardant composed of the two and APP can effectively improve the flame retardancy of the composite film. When the additions of APP, PA, and GO were 10, 3, and 0.75%, respectively, the LOI value of the IFR/TPU composite material reached 29.5, the flame-retardant grade reached V-0, and its peak heat release rate, total heat release, peak smoke production rate, and total smoke release were 86.0, 64.9, 70.5, and 21.7%, greatly lower than pure TPU, respectively. The flame retardancy of the spacer composite membrane constructed from Ti-7 was significantly improved, and the burn-through time of the single-layer film sample was increased by 2.22 times, and the double-layer film sample was increased by 2.63 times. [ABSTRACT FROM AUTHOR]

With the widely application of thermoplastic polyurethane elastomer (TPU), the fire safety of the TPU composites has attracted more and more attention. In this work, a highly efficient and green flame retardant (DA-APP) was synthesized via the ion exchange reaction between biologically relevant molecule dopamine (DA) and ammonium polyphosphate (APP). When the incorporation amount of DA-APP was 5 wt%, it was found that TPU/DA-APP5 passed the V-0 rating and the LOI reached to 25.9%. Meanwhile, the peak heat release rate (PHRR) of TPU composite decreased by 732.5 kW m−2 and total heat release decreased by 19.7 MJ m−2 and total smoke release decreased by 33.6 m2 compared to that of the neat TPU. Moreover, the flame-retarding mechanism of TPU/DA-APP5 was analyzed by TG-FTIR and Raman characterization. The results showed that DA-APP produced amino compounds and phosphoric acid at low temperature, promoted TPU to produce water and carbon dioxide, and diluted oxygen concentration during combustion. In addition, the dense carbon layer formed on the surface of TPU played an important role to isolate the diffusion of heat and oxygen. [ABSTRACT FROM AUTHOR]

In order to apply the rigid biodegradable PLA material for flexible toothbrush bristle products, in this paper, Poly(lactic acid) (PLA) and thermoplastic polyurethane elastomer (TPU) blends (TPU/PLA composites), with a mass ratio of 80:20, were prepared by the melt-blending method to achieve toughening modification. Infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry and low-field nuclear magnetic resonance were used to investigate the effect of the compatibilizer, Maleic anhydride grafted polypropylene (PP-g-MAH), on the compatibility of the blends, and the effect of melamine on the flame retardant properties of the blends was further investigated. The results demonstrated that 3% PP-g-MAH had the best compatibility effect on PLA and TPU; the TPU/PLA composites have a better macromolecular motility and higher crystallization capacity in the amorphous regions through the physical and chemical action by using PP-g-MAH as a compatibilizer. By adding melamine as a flame retardant, the scorch wire ignition temperature of TPU/PLA composites can reach 830 °C, which was elevated by 80 °C compared with pure PLA; however, the flame retardant effect of melamine in a single system was not significant. Melamine acts as a flame retardant by absorbing heat through decomposition and diluting the combustible material by producing an inert gas. [ABSTRACT FROM AUTHOR]

Thermoplastic polyurethane elastomer (TPU) had a wide application because of the perfect property, while it was still limited by its flammability and flame dripping. In this paper, modified molecular sieve (MMS) by 1-((ethoxycarbonyl)methyl)-3-methylimidazolium hexafluorophosphate ([EOOEMIm][PF6]) was used into TPU as a type of flame agent. The flame-retardant performance of TPU was studied by cone calorimeter (CCT), smoke density test (SDT) and thermogravimetric/infrared spectroscopy (TG-IR), respectively. CCT test indicated that MMS improved flame-retardant performance of TPU effectively by promote the formation of char layer. The peak heat release rate and total heat release declined by 48.4% and 32.5%, respectively, compared to pure TPU when 1.0 mass% MMS was added; SDT test showed that MMS improved the smoke generation performance of TPU without flame; and the TG-IR test proved that MMS improved the thermal stability of TPU even though in nitrogen. So the MMS can apply for flame-retardant TPU well in the future. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Three citrates, which incorporate cobalt citrate (CoC), copper citrate (CuC), and yttrium citrate (YC), were combined with ammonium polyphosphate (APP) as a flame retardant to improve the flame retardancy and thermal stability of thermoplastic polyurethane (TPU). The cone calorimeter test (CCT) results demonstrated that the PHRR (peak heat release rate) values of TPU‐2, TPU‐3, and TPU‐4 were decreased from 271.4 kW/m2 for TPU‐1 to 188.0, 256.9, and 219.0 kW/m2, respectively. Besides, compared with TPU‐1, the release of CO and CO2 of TPU composites that containing citrate were decreased. The limiting oxygen index (LOI) value for TPU‐1 (containing 8.0 wt% APP) was 26.5% while that of TPU‐4 was increased to 27.5% and reached to V‐0 rating on the vertical burning test. Thermogravimetric analysis (TG) indicated that containing both APP and citrate accelerated the degradation of TPU composites but increased the char residue. In detail, the char residue of TPU‐0 was 6.3 wt% at 685°C, while that of TPU‐3 was reached to 45.2 wt% at N2 atmosphere. Laser Raman spectroscopy (LRS) showed that the degree of graphitization of TPU composites had been increased after adding the citrates. X‐ray photoelectron spectrometer (XPS) and gas chromatography/mass spectrometry (GC‐MS) illustrated that citrate and APP exerted barriers effect in the condensed phase. This work provided a new way of flame retardant that integrated with citrate and APP for TPU composites. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, 1-aminoethyl-3-methylimidazolium hexafluorophosphate ([APMIm]PF6) and 1-butyl-3-methylimidazolium hexafluorophosphate ([EMIM]PF6) were used as flame retardant additives in thermoplastic polyurethane elastomer (TPU). The flame retardant effect of [APMIm]PF6 and [EMIM]PF6 in TPU had been investigated by cone calorimeter (CCT), scanning electron microscope (SEM), energy-dispersive spectroscopy (EDS), microcombustion calorimeter (MCC), fourier transform infrared spectroscopy (FT-IR), smoke density test (SDT), thermogravimetric analysis (TG) and thermogravimetric/fourier transform infared spectroscopy (TG-IR), respectively. The results indicated that TPU/[APMIm]PF6 had better thermal properties compared with pure TPU and TPU/[EMIM]PF6. The peak heat release rate (pHRR) of TPU/A-1.0 was remarkably reduced by 32.97% and 19.15%, in comparison with that of TPU and TPU/E-1.0. Moreover, the total heat release (THR) and smoke production rate (SPR) of TPU/A-1.0 were the lowest among all samples. And, in the early stage of fire, [APMIm]PF6 can promote the formation of protective carbon layer, reduce the HRR and SPR. Therefore, it is necessary to develop environment-friendly green flame retardants. [ABSTRACT FROM AUTHOR]

In this work, nickel citrate (NC) was combined with ammonium polyphosphate (APP) to improve the flame retardance of thermoplastic polyurethane (TPU). And, the influence of nickel citrate on the flame retardance of TPU/APP composites was investigated by cone calorimeter test (CCT), thermogravimetric analysis/infrared spectrometry (TG-IR), scanning electron microscope (SEM), gas chromatography/mass spectrometry (GC-Ms), and X-ray photoelectron spectrometer (XPS), respectively. It has been found the combination of NC and APP improved the flame retardancy and reduced the total heat release (THR) of TPU composites. The THR value of TPU/APP/NC0.5 was reduced by 20.7% at 750 s compared with that of TPU/APP. The flame retardancy of TPU composites and the graphitization degree of char residue from TPU composites were improved by the combination of both NC and APP. This work provided a new way to improve the flame retardancy of polymer composites. [ABSTRACT FROM AUTHOR]

Molecular sieve was applied to chemical industry diffusely as a typical catalyst. Meanwhile, much molecular sieve was abandoned, which leads to the waste of resources and environmental pollution. It became a research hot spot to recycle abandoned molecular sieve (AMS). In this paper, AMS was used as a flame-retardant and smoke-suppressant agent in TPU. The performance of flame retardant and smoke suppressant of samples was tested by cone calorimeter, smoke density test and thermogravimetric/infrared spectroscopy (TG–IR), respectively. The results showed that AMS could improve the performance of flame retardant and smoke suppressant of TPU effectively. The pHRR and TSR declined by 55.0% and 48.4%, respectively, and the luminous flux increased 5.53% when the addition of molecular sieve was 1.0 mass%. TG–IR results showed that AMS can improve the thermal stability of TPU even under nitrogen atmosphere. It can be concluded that AMS has a good application prospect in flame retardant and smoke suppressant of TPU, and a new idea for the disposal of AMS was provided. [ABSTRACT FROM AUTHOR]

In this paper, fumaric acid (FA) which was a new type of environmental and low‐cost flame retardant was applied for thermoplastic polyurethane elastomer (TPU). The flame‐retardant properties of TPU were tested using limiting oxygen index, cone calorimeter test, smoke density test, and thermogravimetric/Fourier transform infrared spectroscopy. It has been proved that FA could improve the difficulty of the ignition of the sample; the limiting oxygen index value of the sample (FA‐4) increased by 29.7% when 2.0 wt% FA was added to TPU. The cone calorimeter test showed that FA can greatly reduce heat release and smoke production during the combustion process of TPU composites. For example, compared with the pure TPU, the peak heat release rate and total smoke release of the sample (FA‐4) with 2.0 wt% FA were decreased by 50.8% and 51.5% respectively. The results of smoke density test showed that the luminous flux of the samples contained 0.5 wt% FA was increased by 79.2% compared with the pure TPU. The TG results revealed that the sample of FA‐4 had higher char residue content compared with the sample of TPU. The results of thermogravimetric/Fourier transform infrared spectroscopy proved that FA could decrease the initial decomposition temperature for TPU composites and increase the release of CO2 and H2O. All results of test illustrated that FA had good flame‐retardant effect on TPU. [ABSTRACT FROM AUTHOR]

In this paper, a new type of flame retardant (AF‐Fe) based on para‐aramid fiber (AF) which was modified with iron diethyl phosphinate was applied for thermoplastic polyurethane elastomer (TPU). The flame‐retardant properties of TPU were tested using cone calorimeter test, smoke density test, and thermogravimetric analysis/infrared spectrometry. The cone calorimeter test showed that AF‐Fe can greatly reduce the heat release rate, total heat release, smoke factor, and other parameters of TPU composites compared with the sample of TPU/AF. For example, the pHRR of the composite with 1.0 wt% AF‐Fe was reduced by 15.19% compared with the sample with the same content of pure AF. In addition, the smoke factor of TPU/AFFe3 was reduced by 50.52% and 15.63% compared with TPU0 and TPU/AF respectively. The results of smoke density test showed that the luminous flux of TPU/AFFe3 was increased by 79.26% compared with the sample of TPU/AF. The TG results revealed that the sample with TPU/AFFe3 had lower weight loss rate and higher char residue content at 700°C compared with the sample of TPU/AF. [ABSTRACT FROM AUTHOR]

Thermoplastic polyurethane elastomer (TPU) is an easily flammable materials with serious droplets and smoke toxicity, which critically restrict its practical application. In order to improve the flame retardancy of TPU, the present work designed a halogen free flame retardant (AL-APP) containing phosphorus and nitrogen elements via the modification of ammonium polyphosphate (APP) with sodium alendronate (Al). It was found that the limiting oxygen index of TPU/AL-APP 5 composites increased from 20.7 % to 26.5 % and got past the V-0 rating without any droplets in the UL-94 vertical measurement. Meanwhile, the peak heat release rate (PHRR) and total heat release (THR) of TPU/AL-APP 5 system reduced from 1021 to 255 kW/m2 and 87.5–61.2 MJ/m2 in cone calorimeter (CC) measurement when comparing to that of purchased TPU. According the thermogravimetric-infrared and Raman spectroscopy results, the production of the inert gas and formation of continuous carbon layer of AL-APP mutually improved the fire safety of TPU composites. Furthermore, the elongation at break of TPU/AL-APP 5 was significantly increased by 19.9 % than that of neat TPU, showing a better softness and elasticity than neat TPU. According the above results, it was concluded that this work advancing in the high flame-retarding efficient and good mechanical property for TPU composites via a simple method. [Display omitted] [ABSTRACT FROM AUTHOR]

• A completely exfoliated structure of APP–MMT nanocomposite was applied to TPU. • The synergistic effect between APP–MMT nanocomposite and CFA was superior to APP and CFA, and the char was greatly improved. • The pHRR and THR of TPU composites with APP–MMT/CFA (3:1) composite were reduced by 78.2% and 36.6%, respectively. • APP–MMT nanocomposite could improve the dispersion of CFA in the TPU, and the mechanical properties of TPU composites was better than that of TPU with CFA alone. A completely exfoliated structure of ammonium polyphosphate/montmorillonite (APP–MMT) nanocomposite was prepared and applied to thermoplastic polyurethane (TPU) to prepare TPU composites containing APP–MMT and a charring–foaming agent (CFA), after which the properties were compared with those of TPU/APP/CFA composites. The thermal decompositions of TPU composites were investigated by thermal gravimetric analysis. The synergistic effect between APP–MMT and CFA was superior to that of APP and CFA, and the char residue was greatly improved. The flame retardancy of TPU composites was studied by limited oxygen index (LOI) measurements, UL-94 testing, and cone calorimeter test. The APP–MMT nanocomposite promoted the compactness and strength of the char layer formed by the combustion of the TPU composites. The CFA improved the thermal stability of TPU. Compared with TPU/APP/CFA composites, the peak release rate (pHRR) of TPU/APP–MMT/CFA composites were lower and the LOI were higher. When the APP–MMT/CFA compound proportion was 3:1 in weight, the LOI was 25.4%, the pHRR and total heat release of the TPU composites decreased by 78.2% and 36.6%, respectively, and the smoke production and CO emission were restrained. The mechanical properties and morphology of TPU composites were analyzed by tensile strength, elongation at break, and scanning electron microscopy. The APP–MMT composite improved the dispersion of CFA in the TPU, and the mechanical properties of TPU/APP–MMT/CFA composites were higher than that of TPU with only CFA. The structure of residual carbon was studied by X-ray photoelectron spectroscopy, and it was confirmed that the APP–MMT composite promoted the formation of a good protective carbon layer during the combustion of the TPU composites and improved its flame retardancy. [ABSTRACT FROM AUTHOR]

• A highly efficient and halogen-free flame retardant Co-PDA-APP was prepared by modifying the surface of ammonium polyphosphate (APP) with dopamine (DA) and cobalt ions (Co). • Co-PDA-APP can significantly improve the flame retardancy of TPU by working in the condensed and gas phases. • The tensile strength of flame-retarding composites was 24.4 MPa, which was preserved at a high level comparing to that of TPU/APP 3 composites. Fire safety and environmental friendliness are the two key factors for the industrial application of polymer-based composites; hence, highly efficient and halogen-free flame-retarding polymer composites have been developed to achieve the above attributes. In the present work, halogen-free flame retardant Co-PDA-APP was prepared by modifying the surface of ammonium polyphosphate (APP) with dopamine (DA) and cobalt ions (Co) to enhance the fire safety of thermoplastic polyurethane elastomer (TPU). When only 3 wt% of Co-PDA-APP was added, the limiting oxygen index (LOI) reached to 25% and passed the V-0 rating in UL-94 test. The peak of heat release rate (PHRR) and peak of smoke production rate (PSPR) decreased by 66.0% and 76.4% comparing to the relative values of neat TPU. Moreover, thermogravimetry Fourier-transform infrared and Raman spectroscopy were carried out to investigate the flame-retardant mechanism of Co-PDA-APP in the TPU composite. The intumescent flame-retardant mechanism was found to be dominant, and APP, PDA, and Co promoted the formation of a physical barrier and enhanced the fire safety of the TPU composite. Furthermore, the tensile strength was 24.4 MPa, which was preserved at a high level comparing to that of TPU/APP 3 composites. [ABSTRACT FROM AUTHOR]

Developing highly effective flame retardant polymeric materials with the release of low toxic fumes during burning still keep a huge challenge. In this work, we demonstrated successful synthesis of titanium carbide-reduced graphene oxide (Ti 3 C 2 T x -rGO) hybrid via hydrogen bonding induced assembly of Ti 3 C 2 T x and rGO, which was utilized to improve the thermal and fire safe performances of thermoplastic polyurethane elastomer (TPU). The results indicated that the Ti 3 C 2 T x -rGO hybrid showed a strong adhesion and good compatibility with TPU host. Furthermore, as-prepared Ti 3 C 2 T x -rGO hybrid was homogeneously dispersed in the TPU matrix due to the mutual intercalation of rGO and Ti 3 C 2 T x preventing the re-aggregation. The thermal stability of TPU was dramatically improved after the introduction of Ti 3 C 2 T x -rGO. With addition of 2.0 wt% Ti 3 C 2 T x -rGO, the peak of smoke production rate and total smoke release of TPU nanocomposite were remarkably decreased by 81.2% and 54.0%, respectively. In addition, the TPU/Ti 3 C 2 T x -rGO-2.0 showed distinct reductions in the peak of carbon monoxide production rate (54.1%) and total carbon monoxide yield (46.2%). The physical barrier effect, the catalytic charring of Ti 3 C 2 T x -rGO hybrid and the chemical transformation of Ti 3 C 2 T x were responsible for the excellent fire resistance of TPU/Ti 3 C 2 T x -rGO systems. This work provides a novel strategy to significantly reduce the fire hazards of TPU, thus broadening its industrial applications. Image 1 [ABSTRACT FROM AUTHOR]