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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]

Using intumescent flame retardant (IFR) composed of ammonium polyphosphate (APP) and pentaerythritol (PER) as the main flame retardant, the organic montmorillonite (OMMT) as the synergistic flame retardant, and the thermoplastic polyurethane elastomer (TPU) as the polymer charring agent, the flame retardant modification of polybutylene succinate (PBS) was carried out by melt blending. The effect of the distribution of IFR and OMMT on the flame retardancy of PBS/TPU blends was investigated. The PBS/TPU/IFR/OMMT flame retardant composites were tested and characterized by limiting oxygen index (LOI), vertical combustion, thermogravimetric analysis, melt viscosity analysis and scanning electron microscopy (SEM). The results show that OMMT and IFR has a good synergistic flame retardant effect. The flame retardant effect of PBS/TPU/IFR blends can be improved when the mass fraction of OMMT is 1%. The distribution position of IFR and OMMT has a significant impact on the flame retardance of PBS/TPU/IFR/OMMT blends. When IFR and OMMT are directly distributed in PBS phase, the flame retardancy of the blend is the best. LOI is 32. 7% and the vertical combustion reaches UL 94 V-0 level, which is significantly better than that of the flame retardancy for the other three distribution systems. [ABSTRACT FROM AUTHOR]

This research addresses the challenge of determining the optimal parameters for the selective laser sintering (SLS) process using thermoplastic polyurethane elastomer (TPU) flexa black powder to achieve high-quality SLS parts. This study focuses on two key printing process parameters, namely layer thickness and the laser power ratio, and evaluates their impact on four output responses: density, hardness, modulus of elasticity, and time required to produce the parts. The primary impacts and correlations of the input factors on the output responses are evaluated using response surface methodology (RSM). A particular response optimizer is used to find the optimal settings of input variables. Additionally, the rationality of the model is verified through an analysis of variance (ANOVA). The research identifies the optimal combination of process parameters as follows: a 0.11 mm layer thickness and a 1.00 laser power ratio. The corresponding predicted values of the four responses are 152.63 min, 96.96 Shore-A, 2.09 MPa, and 1.12 g/cm3 for printing time, hardness, modulus of elasticity, and density, respectively. These responses demonstrate a compatibility of 66.70% with the objective function. An experimental validation of the predicted values was conducted and the actual values obtained for printing time, hardness, modulus of elasticity, and density at the predicted input process parameters are 159.837 min, 100 Shore-A, 2.17 MPa, and 1.153 g/cm3, respectively. The errors between the predicted and experimental values for each response (time, hardness, modulus of elasticity, and density) were found to be 4.51%, 3.04%, 3.69%, and 2.69%, respectively. These errors are all below 5%, indicating the adequacy of the model. This study also comprehensively describes the influence of process parameters on the responses, which can be helpful for researchers and industry practitioners in setting process parameters of similar SLS operations. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS 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.)

Lightweight, flexible and high-performance (high efficiency and low reflection) electromagnetic interference (EMI) shielding materials are urgently needed to cope with the increasingly complex electromagnetic (EM) radiation environment. In this study, the thermoplastic polyurethane/expanded graphite/silver (TPU/EG/Ag) composite foams with three-dimensional (3D) isolated conductive network were successfully manufactured through the combination of supercritical carbon dioxide (scCO2) foaming and chemical deposition. This composite foam achieves a conductivity up to 171.2 S/m and an EMI SE of 56.3 dB with only 0.58 vol% Ag on account of the volume exclusion of pores and the selective enrichment of Ag nanoparticles. The weight reduction rate of the composite exceeds 74%, and the density of the foamed sample can be as low as 0.21 g/cm3 by introducing a porous structure. Interestingly, the presence of porosity also alleviates impedance mismatch between the composites and air, and the reflectivity of composite is reduced from 99% to 31% owing to the multiple absorption in porous structure, which significantly weakens the serious secondary EM radiation pollution. Moreover, benefiting from the secondary melting at the interface of the TPU isolation unit, these composite foams exhibit favorable compressible recovery performance and shielding stability after 50 cycles of compression. This work proposes a new idea for the lightweight and flexible design of EMI shielding composites, opening a new path for the development of next-generation absorption-based EMI shielding materials.

To study the effect of soft segments of thermoplastic polyurethane elastomer (TPU) material on the sealing performance of hydraulic cylinders, a series of TPU materials were synthesized by polybutylene adipate diol (PBA),polycarbonate diol (PCDL), polycaprolactone diol(PCL), polytetrahydrofuran ether diol ( PTMEG ), diphenyl methane-4, 4'--diisocyanate (MDI) and hydroquinone dihydroxyethyl ether (HQEE).The effects of soft segment types on physical and mechanical properties, friction and wear properties, hydraulic oil aging properties and sealing properties of TPU materials were studied. The results show that the four kinds of TPU materials synthesized by four soft segments have good physical and mechanical properties. PBA-type TPU material has the best wear resistance, and the friction coefficient of the TPU materials synthesized by four soft segments under the condition of hydraulic oil lubrication is 0. 05, indicating a lower friction coefficient. PCDL--type TPU material has the best tolerance to hydraulic oil and sealing performance. PCDL--type TPU material is an ideal material for manufacturing hydraulic cylinder seals. [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]

With the release of the domestic plastic restriction order, degradable plastics have become a current research hotspot. The cost of packaging bags made from widely used degradable plastics such as PLA, PBAT and other plastic masterbatches is high, and it cannot well adapt to the existing market rules. The PBS plastic was foamed and adhered to the paper material by using TPU and starch to prepare a new type of degradable packaging bag. This new type of degradable packaging bag has a resilience of 153 N on one side and a degradation rate of 52.6% in 45 days. It is low in cost, environmentally friendly and non-toxic. It is a good choice for promoting degradable plastics. [ABSTRACT FROM AUTHOR]

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research Institute 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.)

A double-coated MAPbBr 3 with dynamic hydrogen bonding network was constructed by amino-terminated hyperbranched aminoglycoside polymer (AHP) and thermoplastic polyurethane (PUIP). The thermal and water degradation of MAPbBr 3 was greatly alleviated upon formation of the MAPbBr 3 @AHP@PUIP composite. The double-coated MAPbBr 3 @AHP@PUIP film exhibited high quantum efficiency and excellent luminescence stability at room temperature, with quantum yields remained above 90% of the original value even after 20 days in air, and also exhibited excellent water resistance, thermal responsiveness, and self-healing properties. This inexpensive and convenient method not only greatly enhanced PL efficiency, increased water stability, but also demonstrated excellent flexibility and elasticity, suggesting broad prospects for the commercial application of inorganic perovskite materials in flexible electronics. [Display omitted] • A double-coated MAPbBr 3 with dynamic hydrogen bonding network was constructed by AHP and PUIP. • The thermal and water degradation of MAPbBr 3 was greatly alleviated upon formation of the MAPbBr 3 @AHP@PUIP composite. • The double-coated MAPbBr 3 @AHP@PUIP film exhibited high quantum efficiency and excellent luminescence stability at room temperature. • The double-coated MAPbBr 3 @AHP@PUIP film exhibited exhibited excellent water resistance, thermal responsiveness, and self-healing properties. MAPbX 3 (X = Br, I, Cl) type lead halide perovskite has great potential for light-emitting devices due to its excellent optical properties; however, their degradation under the influence of heat and atmospheric moisture severely limited their applications. To address this issue, we used a dynamic hydrogen bonding network constructed by amino-terminated hyperbranched aminoglycoside polymer (AHP) and thermoplastic polyurethane (PUIP) to double-coat MAPbBr 3. The thermal and water degradation of MAPbBr 3 was greatly alleviated upon formation of the MAPbBr 3 @AHP@PUIP composite. The structures of AHP, PUIP, MAPbBr 3 @AHP, and MAPbBr 3 @AHP@PUIP films were characterized by various techniques. The double-coated MAPbBr 3 @AHP@PUIP film exhibited high quantum efficiency and excellent luminescence stability at room temperature, with quantum yields remained above 90 % of the original value even after 20 days in air. Moreover, the polymer film still maintains high fluorescence emission after 72 h in the water phase, and can achieve fluorescence recovery transformation at a specific temperature, and has a good self-healing property at room temperature. This inexpensive and convenient method not only greatly enhanced PL efficiency, increased water stability, but also demonstrated excellent flexibility and elasticity, suggesting broad prospects for the commercial application of inorganic perovskite materials in flexible electronics. [ABSTRACT FROM AUTHOR]

Firstly, GO was modified by isophorone diisocyanate (IPDI). GO was successfully grafted with isocyanate (-NCO) by FTIR. Then, in-situ polymerization was used to react polytetramethylene ether glycol 1000 (PTMG 1000) with —NCO on modified GO (IGO), and then prepolymerized with diphenylmethylene diisocyanate (MDI) to prepare IGO @ thermoplastic polyurethane elastomer (TPU) nanocomposites. As a comparison, GO was added during the pre polymerization of MDI and PTMG 1000, and GO/TPU composite materials were prepared by solution blending method. The results indicated that, compared to GO/TPU and pure TPU, IGO@TPU had better mechanical properties. The tensile strength and elongation at break of IGO@TPU were 36 MPa and 570.5% respectively, which increased by 338% and 70.6% compared with TPU and 188% and 61.5% compared with GO/TPU.

This research addresses the challenge of determining the optimal parameters for the selective laser sintering (SLS) process using thermoplastic polyurethane elastomer (TPU) flexa black powder to achieve high-quality SLS parts. This study focuses on two key printing process parameters, namely layer thickness and the laser power ratio, and evaluates their impact on four output responses: density, hardness, modulus of elasticity, and time required to produce the parts. The primary impacts and correlations of the input factors on the output responses are evaluated using response surface methodology (RSM). A particular response optimizer is used to find the optimal settings of input variables. Additionally, the rationality of the model is verified through an analysis of variance (ANOVA). The research identifies the optimal combination of process parameters as follows: a 0.11 mm layer thickness and a 1.00 laser power ratio. The corresponding predicted values of the four responses are 152.63 min, 96.96 Shore-A, 2.09 MPa, and 1.12 g/cm3 for printing time, hardness, modulus of elasticity, and density, respectively. These responses demonstrate a compatibility of 66.70% with the objective function. An experimental validation of the predicted values was conducted and the actual values obtained for printing time, hardness, modulus of elasticity, and density at the predicted input process parameters are 159.837 min, 100 Shore-A, 2.17 MPa, and 1.153 g/cm3, respectively. The errors between the predicted and experimental values for each response (time, hardness, modulus of elasticity, and density) were found to be 4.51%, 3.04%, 3.69%, and 2.69%, respectively. These errors are all below 5%, indicating the adequacy of the model. This study also comprehensively describes the influence of process parameters on the responses, which can be helpful for researchers and industry practitioners in setting process parameters of similar SLS operations.

The purpose of this paper lies in the preparation and utilization of phenolic resin hollow microspheres to enhance the induced carbonization performance of polymer materials and endow higher fire safety. PHM (phenolic resin hollow microspheres), CPHM (carbonized phenolic resin hollow microspheres), and CAPHM (carbonized phosphorylated phenolic resin hollow microspheres) were used as fillers in thermoplastic polyurethane elastomer. With the incorporation of 4 wt.% CPHM, as compared to pure TPU, the peak heat release rate (pHRR), total smoke release (TSR), and the peak CO release rates are decreased by 64.4%, 37.9%, and 86.2%, respectively. Simultaneous enhancement in flame retardancy, smoke suppression, and toxicity reduction is attributed to the formation of a compact residual layer in the polymer matrix, which significantly retards the dispersion of combustible gas, smoke particles, and toxic gas from the underlying substrate. Such outstanding characteristics make carbon microspheres a promising candidate for high fire safety polymers. [ABSTRACT FROM AUTHOR]

Thermoplastic polyurethane was an important polymer and widely used in many fields. However, poor fire performance significantly inhibits its further application. In this study, the flammability, thermal and mechanical properties of thermoplastic polyurethane (TPU)/DOPO derivative (DiDOPO)/sepiolite composites, fabricated by a melt blending process, were examined based on the sepiolite content. TPUSEP3 has achieved UL-94 V0 classes and LOI 34.4%. Micro-scale combustion calorimeter shows that TPU/DiDOPO/sepiolite composites possess an excellent fire performance. Flexural strength of TPUSEP3 has enhanced to 48.3 MPa which indicated the rigidity of composites has significantly improved. In addition, the scanning electronic microscopy images of the external surface of the carbon layer of composites show a very compact structure. Sepiolite and DiDOPO change the decomposition process of composites lead to the decrease of Ea values of TPU/DiDOPO/sepiolite composites. [ABSTRACT FROM AUTHOR]

In this paper, phenolic resin hollow microspheres (PHM) were prepared using in-situ polymerization and used as flame-retardants for TPU. The structure and composition of PHM were characterized by Scanning Electron Microscope (SEM). The potential of PHM as flame retardant was verified by thermogravimetric analysis (TG). Then, the flame retardancy and toxicity reduction of PHM in TPU/PHM composites were verified by cone calorimeter test (CCT) and Thermogravimetric Analysis-infrared Spectrometry (TG-IR). It has been found that comparing TPU/PHM-4 sample containing 4.0 wt% PHM with pure TPU, the peak heat release rate (pHRR) was reduced by 61.6%, the total smoke release (TSR) by 23.2%, and the CO production by 86.2%, respectively. The SEM, Laser Raman Spectroscopy Test (LRS), and other tests were carried out to test the char residues after CCT, and the mechanism of PHM in the process of flame retardant TPU was reasonably deduced. In a word, PHM is very effective as a flame retardant of TPU.

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.

Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & Technology Editorial Office 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.)

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS 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 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]

This article mainly studied novel hollow carbon microspheres modified with molybdenum compounds for flame retardancy and toxicity reduction in thermoplastic polyurethane (TPU) elastomer. The structure of hollow carbon spheres (HCS) was investigated by X‐ray photoelectron spectroscopy and scanning electron microscopy‐energy‐dispersive spectrometer, respectively. The specific molybdenum compounds on the surface of HCS were further investigated by X‐ray diffraction. The flame retardancy and toxicity reduction of hollow carbon microsphere in TPU composites were studied by cone calorimeter, thermogravimetric analysis, and Fourier transform infrared spectroscopy, and so forth. The result shows that HCS modified by molybdenum compounds (MOH) can reduce fire hazards and toxic release of TPU during combustion. For example, under the same load, the peak heat release rate of TPU/MOH composite decreased by 63.39%, that of TPU composite prepared by modified HCS with ammonium molybdate (TPU/AMH) decreased by 52.89%, and that of TPU composite prepared by introducing acidulated carbonized HCS (TPU/CAH) decreased by 40.73%, compared with that of pure TPU. The peak smoke production rate (pSPR), peak carbon monoxide production (pCOP), and peak carbon dioxide production (pCO2P) of TPU/MOH composite decreased by 52.34%, 72.4%, and 68.3%, respectively. Therefore, there is a novel strategy to incorporate modified HCS to TPU, facilitating its widely promising applications in TPU. [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.)

Hypothesis: Thermoplastic polyurethane elastomers are generally synthesized by one of the methods of one-shot, pre-polymer and semi pre-polymer. In the preparation of polyurethanes by these methods the viscosity is increased as the reaction progresses, while the reaction is difficult to control. Therefore, the reaction extrusion method has received much attention in recent years due to high temperature reaction, better mixing of components and more convenient reaction control as well as increased reaction rate due to the elimination of post curing time. The purpose of this study was to study the process parameters of polyurethane elastomer synthesis using reactive extrusion.Methods: Here a prepolymer was synthesized with a polyester polyol (based on adipic acid) and diphenyl methane diisocyanate in a glass reactor. Then butanediol chain extender was added to the prepared prepolymer in a micro extruder at three different temperatures and residence times to obtain the final polymer. FTIR and intrinsic viscosity tests were then taken from 9 prepared samples to determine the optimum temperature and residence time.Finding: The results showed that the temperature of 165°C and the residence time of 10 min were the optimum conditions for the elastomer synthesis through reactive extrusion. Then, by designing three formulations, three thermoplastic elastomer specimens were prepared by adding butanediol chain extender to the prepolymers, in a micro-extruder, and their physical mechanical properties were studied. The results showed that using this method and the obtained process conditions, it is possible to provide polyurethane thermoplastic elastomers with desirable properties in shorter time.

Sodium fumarate (SF, C4H3NaO4), as a low‐cost and environment‐friendly additive, has been applied as the fire safety agent to investigate the flame retardancy and smoke suppression property in thermoplastic polyurethane elastomer (TPU). A series of tests were carried out, including limiting oxygen index (LOI), cone calorimeter test (CCT), smoke density test (SDT), and thermogravimetric/Fourier transform infrared spectroscopy (TG‐IR). The results proved that the addition of SF can significantly improve the fire safety property of TPU. Remarkably, in the case of the sample containing 2.0 wt% SF, LOI was raised up to 27.5 compared with 21.0 of pure TPU. The CCT results showed that pHRR, THR, TSR, and SF values decreased by 60.1%, 17.0%, 44.6%, and 66.4%, respectively, while the residual mass increased from 3.0% to 12.3% compared with pure TPU. The digital photographs displayed a more compact and intense carbon layer after the addition of SF. The SDT results indicated SF has increased the luminous flux and reduced Ds values, implying the improvement of the smoke suppression property of TPU. TG and TG‐IR results showed that the addition of SF has promoted the char forming process and reduced the release of CO2 and other volatile compounds. All results of tests illustrated that SF has considerable fire safety effect on TPU. Through the analysis of the results of this experiment, it will make a significance in the aspect of fire safety of polymer. [ABSTRACT FROM AUTHOR]

With the aim to improve the compatibility of polycarbonate (PC)/polypropylene (PP) blends, a novel aromatic polycarbonate diol (PCDL) was synthesized by the transesterification reaction, then a series of polycarbonate‐based thermoplastic polyurethane elastomers compatibilizers (TPU‐Gx) with octadecyl side chains were successfully prepared by introducing different content of PCDL and glyceryl monostearate (2,3‐Dihydroxypropyl octadecenoate; GMS). The structures of synthesized products were confirmed by Fourier transform infrared spectroscopy and Nuclear magnetic resonance hydrogen spectroscopy. Thermogravimetry results showed that all TPU‐Gx had good thermal stability. The effects of TPU‐Gx on the compatibilization of PC/PP blends were investigated in the aspect of morphology, mechanical, thermal, and rheological properties. The results showed that all TPU‐Gx could enhance the interfacial adhesion between PC/PP and improve the mechanical properties of PC/PP blends. Among them, the addition of TPU‐G1.5 containing 6.0 wt% PCDL and 1.5 wt% GMS made PC/PP/TPU‐G1.5 blends show the highest impact strength, which increased by 54.1% when compared with that of pure PC/PP blends. [ABSTRACT FROM AUTHOR]

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]

As is known there is a large amount of smoke released from the combustion process of thermoplastic polyurethane elastomer (TPU). To reduce the fire risk of TPU is one of the research contents in the fire safety fields. In this paper, [Glu]H2PW12O40 was used as smoke suppressant in TPU, and the smoke suppression effect of [Glu]H2PW12O40 was intensively investigated using nuclear magnetic resonance, scanning electron microscope, cone calorimeter test (CCT), smoke density test (SDT), and thermogravimetric analysis/infrared spectrometry, respectively. In the CCT test, the peak value of smoke production rate (SPR) of TPU-3 with 0.5 mass% of [Glu]H2PW12O40 was 0.036 m2 s−1, reduced by 75% compared with the peak SPR value of TPU-0 without [Glu]H2PW12O40 (0.145 m2 s−1). [Glu]H2PW12O40 could decrease the total smoke release (TSR) from 1560 to 694 m2 m−2. And [Glu]H2PW12O40 could decrease the smoke factor from 1838 to 538 W m−2. The SDT results showed that the luminous flux value of TPU-3 with 0.5 mass% of [Glu]H2PW12O40 decreased by 30% compared with pure TPU at the end of the test without flame. The photographs from the CCT test showed that [Glu]H2PW12O40 could promote char residue formation. TG test also revealed that [Glu]H2PW12O40 could improve the thermal stability at high temperature. At the end of thermal decomposition, the mass of TPU-3 with 0.5 mass% of [Glu]H2PW12O40 increased 6.3% compared with the mass of TPU-0 without [Glu]H2PW12O40. Based on the above result, it could be concluded that [Glu]H2PW12O40 can suppress smoke generation by promoting char generation. In addition, [Glu]H2PW12O40 has a good prospect in smoke suppression of TPU. [ABSTRACT FROM AUTHOR]

In this study, three types of bionic texture surfaces were designed, based on the microstructure of tree frog and gecko feet, for two typical prosthetic substrates: silicone rubber and thermoplastic polyurethane elastomer (TPU). The surface energy of all bionic texture surfaces, and the relative displacement and energy dissipation of the reciprocating friction between these bionic surfaces and skin, were investigated. The results revealed that the bionic texture of the prosthetic socket surface had an obvious influence on the surface characteristics and reciprocating characteristics of friction with the skin. According to the comprehensive weight rating method, the optimal bionic textures for the silicone rubber substrate were a regular hexagonal prism and a quadrangular prism; for the TPU substrate, only the regular quadrangular prism texture was optimal. These textures can effectively increase the surface energy of the surface of the prosthetic socket, thereby increasing its adhesion to skin and reducing the dissipation of friction energy when it interacts with the stump. This bionic prosthetic socket surface design helps improve the adaptation between the prosthetic socket and the stump.

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]

Thermoplastic polyurethane (TPU) elastomer has a widely application because of its perfect physical and chemical properties. However, it was limited by its low reliability in fire safety. In this paper, a new fire agent integrated with molecular sieve and tetrafluoroborate ionic liquid ([EOOEMIm][BF4]) was used to improve fire safety of TPU. The fire safety of TPU composites was investigated by cone calorimeter test, smoke density test, and thermogravimetric/infrared spectroscopy, respectively. The results showed that modified molecular sieve (MMS) can improve fire safety of TPU effectively. The luminous flux increased to 10.10%, total smoke release decreased by 58%, and heat release rate declined of 65% than pure TPU when the addition of MMS was 0.5 wt%. In addition, MMS can improve thermal stability of TPU even in nitrogen according to thermogravimetric/infrared spectroscopy test. These proved that MMS has a satisfactory application prospect in fire safe polymer materials. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the performance of polylactide (PLA)-based materials shaped by the traditional injection molding technique versus three-dimensional (3D)-printing additive manufacturing. Comparisons were performed not only for neat PLA but also for its thermoplastic polyurethane elastomer (TPU) blend and for its E-glass fiber (GF)-reinforced composites. Performance comparison of the injection-molded and 3D-printed specimens was especially conducted to compare their mechanical properties (strength–modulus–toughness) by tensile, flexural, and fracture toughness tests. Other comparisons such as their macro-level appearances, fracture surface morphology, and thermal behavior were also performed by photographic images, scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analysis. It can be concluded that the use of 3D-printing in the shaping of neat PLA and PLA/TPU blend was generally very beneficial; on the other hand, due to the differences in the orientation of the GF reinforcements, there could be certain reductions in the mechanical performance of PLA/GF and PLA/TPU/GF composite specimens. [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]

In this study, polycaprolactone based polyurethane prepolymer (PUP) was used as a compatibilizer to prepare compatible chitosan- thermoplastic polyurethane elastomer (TPU) composites in an intensive mixer. The effects of the PUP content on the structure and properties of the composites were analyzed. The -NCO groups of PUP compatibilizer can interact with -OH or -NH2 groups of chitosan through urethane linkages to improve compatibility between chitosan and PUP. Also, the PUP compatibilizer interacted with the TPU through physical cross-linking due to their similar structures. Thus, between the chitosan and the TPU matrix formed an interface layer, which significantly improved compatibility of the composite. Consequently, the mechanical and morphological characterizations were performed to show that the chitosan-PUP-TPU composites had better performance compared to the chitosan-TPU composite without the compatibilizer. Therefore, the PUP interface structure plays an important role in improving compatibility and performance of the chitosan-TPU composite materials. This work provides a simple and effective method to prepare hydrophilic chitosan/ hydrophobic polymers composites. [ABSTRACT FROM AUTHOR]

Biodegradable blends of poly(l-lactide) (PLL) toughened with a polycaprolactone-based thermoplastic polyurethane (TPU) elastomer and compatibilized with a purpose-designed poly(l-lactide-co-caprolactone) (PLLCL) copolymer were prepared. Both 2-component (PLL/TPU) and 3-component (PLL/TPU/PLLCL) blends of various compositions were prepared by melt mixing, hot-pressed into thin films and their properties tested. The results showed that, although the TPU could toughen the PLL, the blends were immiscible leading to phase separation with the TPU domains distributed in the PLL matrix. However, addition of the PLLCL copolymer could partially compatibilize the blend by improving the interfacial adhesion between the two phases. Biodegradability testing showed that the blends were biodegradable and that the PLLCL copolymer could increase the rate of biodegradation under controlled composting conditions. The 3-component blend of composition PLL/TPU/PLLCL = 90/10/10 parts by weight was found to exhibit the best all-round properties. [ABSTRACT FROM AUTHOR]

ABSTRACT CO2 copolymer diol-based thermal polyurethane elastomers (PPC-TPU) were prepared by the reaction of CO2 copolymer diol and methylene diphenyl diisocyanate and chain extender (ethylene glycol/1,4-butanediol/1,6-hexanediol) (EG/BDO/HG). The rheological and mechanical properties of PPC-TPU were analyzed. The effects of shear rate, shear temperature, hard segment content, and variety of chain extender on the properties of PPC-TPU were studied. The results showed that the apparent viscosity (η) of PPC-TPU decreased with the increasing shear rate ( τ), and the non-Newtonian index ( n) was less than 1. PPC-TPU exhibited a typical character of pseudoplastic non-Newtonian rheological behavior. The degradation during the processing was obviously inhibited by adding plasticizer and antioxidant. It was also discovered that the apparent viscosity varied with the content of hard segment and chain extender. Under the same temperature (185 °C) and shear rate (50 s−1), the apparent viscosity increased considerably with the raise of hard segment content, and the apparent viscosity and tensile strength of PPC-TPU with EG as chain extender was the maximum. It can be seen that with the apparent shear rate increasing, the variation tendency of apparent shear stress levels off, and the nonlinear relationship of τ- γ curve tended to be obvious. PPC-TPU exhibited a typical character of pseudoplastic non-Newtonian rheological behavior. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45974. [ABSTRACT FROM AUTHOR]

This article mainly studied the synergistic fire safety effect between nano-CuO and ammonium polyphosphate (APP) in thermoplastic polyurethane elastomer (TPU). The TPU composites were prepared by molten blending method. And the fire safety of all TPU composites was investigated by LOI test, cone calorimeter test (CCT), microscale combustion colorimeter (MCC) and smoke density test (SDT), respectively. The LOI test showed that nano-CuO could further improve the flame retardancy of TPU. The CCT results showed that there was a remarkably synergistic fire safety effect between APP and nano-CuO in TPU. Remarkably, the total heat release and total smoke release for the sample with 0.5 mass% content of nano-CuO decreased by at least 13.0 and 51.1% compared with the sample containing only APP, respectively. And the residual carbon mass of the samples containing nano-CuO was more than that of the sample with only APP at the end of the test. The MCC results showed that the HRR values of the samples containing nano-CuO were further lower than that of the sample containing APP. The SDT results showed that the luminous flux values of the samples containing nano-CuO were higher than that of the sample with only APP irrespective of with flame or without flame, which indicated that there was an apparently synergistic effect of smoke suppression between APP and nano-CuO in TPU. Through the analysis of the results of this experiment, it will make a great influence on the study of the nanomaterials in the aspect of fire safety of polymer. [ABSTRACT FROM AUTHOR]

The application of fibers is more and more extensive, and the pollution caused by abandoned fibers is getting more serious, which has aroused wide attention. So it is necessary to find a way to solve the problem. In this paper, the para-aramid fiber (AF) was recycled and modified by phosphoric acid, and then was applied as environmental friendly flame retardant for thermoplastic polyurethane elastomer (TPU). The flame retardant properties of TPU were tested using cone calorimeter test (CCT) and thermogravimetric/Fourier transform infrared spectroscopy (TG-IR). The CCT test showed that AF-P had better flame retardant effect on TPU than pure AF. Remarkably, the pHRR value for the sample with 1.00 wt% content of AF-P was decreased by 48.1%; AF-P had improved the char forming progress and the residual mass was 30.6%, which was much more than pure TPU. TG test showed that AF-P could improve the thermal stability of TPU at high temperature. The TG-IR test revealed that AF-P had reduced the release of CO 2 at the beginning. Based on the above results, it will make a great influence on the study of reuse of fibers and environmental friendly flame retardant of polymer. [ABSTRACT FROM AUTHOR]

Este trabalho tem como objetivo a incorporação da mica à matriz do elastômero termoplástico de poliuretano (TPU) tipo poliéter, para o desenvolvimento de novos materiais nos quais as propriedades inerentes da mica possam ser combinadas às do TPU. Este elastômero termoplástico tem alto custo, ao contrário da mica, que é de baixo custo e abundante no Brasil. Os diferentes compósitos, com teores de mica variando de 0 a 20 phr (por cem partes de resina), foram preparados em misturador interno, acoplado a um reômetro de torque Haake. Estes compósitos foram analisados termicamente por análise termogravimétrica (TGA) e análise dinâmico-mecânica (DMA). Foi observado que a incorporação de mica ao TPU altera as propriedades dinâmico-mecânicas bem como a estabilidade térmica deste polímero em diferentes atmosferas. A adição de mica desloca o início da degradação para temperaturas mais baixas nas duas atmosferas (inerte e oxidante) e a temperatura de transição vítrea tem ligeira diminuição com o aumento do teor de mica. Os resultados decorrem principalmente das interações entre a mica e o segmento rígido do TPU, durante o processamento em misturador interno.This work is aimed at incorporating mica to the matrix of a polyether type thermoplastic polyurethane elastomer (TPU), for the development of new materials in which the inherent properties of mica could be combined to those of TPU. This thermoplastic elastomer has high cost, unlike mica, which is inexpensive and abundant in Brazil. The different composites, with the mica contents varying from 0-20 phr (per hundred resin) were prepared in an internal mixer, coupled to a Haake torque rheometer. These composites had their thermal properties analyzed by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The incorporation of mica caused changes in the thermal stability of TPU in different atmospheres and in its dynamic mechanical properties. The addition of mica shifted the onset of degradation to lower temperatures in the two atmospheres (inert and oxidizing), while the glass transition temperature decreased slightly with increasing mica content. The results stem mainly from the interactions between mica and TPU hard segments during processing in the internal mixer.

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]

Extrusion-based (fused filament fabrication) three-dimensional (3D) printing of shape-memory polymers (SMPs) has the potential to rapidly produce highly customized smart-material parts. Yet, the effects of printing parameters on the shape-memory properties of printed SMPs remain poorly understood. To study the extent to which the 3D printing process affects the shape-memory properties of a printed SMP part, here temperature, extrusion rate multiplier, and fiber orientation were systematically varied, and their effect on shape-memory fixing and recovery ratios was evaluated. Fiber orientation, as determined by print path relative to the direction(s) of loading during shape-memory programming, was found to significantly impact the fixing ratio and the recovery ratio. Temperature and multiplier had little effect on either fixing ratio or recovery ratio. To facilitate the use of printed SMP parts in biomedical applications, a cell viability assay was performed on 3D-printed samples prepared using varied temperature and multiplier. Reduction in multiplier was found to increase cell viability. The results indicate that fiber orientation can critically impact the shape-memory functionality of 3D-printed SMP parts, and that multiplier can affect cytocompatibility of those parts. Thus, researchers and manufacturers employing SMPs in 3D-printed parts and devices could achieve improved part functionality if print paths are designed to align fiber direction with the axis(es) in which strain will be programmed and recovered and if the multiplier is optimized in biomedical applications in which a part will contact cells., Competing Interests: No competing financial interests exist., (Copyright 2023, Mary Ann Liebert, Inc., publishers.)