A novel electrospun TPU/PVdF porous fibrous polymer electrolyte for lithium ion batteries

Novel blend-based gel polymer electrolyte (GPE) films of thermoplastic polyurethane (TPU) and poly(vinylidene fluoride) (PVdF) (denoted as TPU/PVdF) have been prepared by electrospinning. The electrospun thermoplastic polyurethane-co-poly (vinylidene fluoride) membranes were activated with a 1M solution of LiClO₄ in EC/PC and showed a high ionic conductivity about 1.6 mS cm⁻¹ at room temperature. The electrochemical stability is at 5.0 V versus Li⁺/Li, making them suitable for practical applications in lithium cells. Cycling tests of Li/GPE/LiFePO4 cells showed the suitability of the electrospun membranes made of TPU/PVdF (80/20, w/w) for applications in lithium rechargeable batteries. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

High-Temperature Bearable Polysulfonamide/Polyurethane Composite Nanofibers’ Membranes for Filtration Application

Polysulfonamide (PSA)-based membranes are widely used for high-temperature filtration. PSA/polyurethane (TPU) composite membranes that can withstand a temperature exceeding 200 °C are fabricated by an electrospinning method. The effects of PSA/TPU mass ratio on the morphology and properties of the prepared composite membranes are investigated to obtain nanofibers with different diameters. These composite membranes are characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and differential scanning calorimetry, and mechanical and filtration properties of membranes are also investigated. The maximum stress and elongation at break of PSA/TPU nanofibers’ membranes reach 13.66 ±1.43 MPa and 75.01 ± 3.78%, respectively, when the PSA/TPU mass ratio is 3:7. Moreover, filtration results show high filtration efficiency (>99%) and low pressure drop for diethyl-hexyl-sebacat (DEHS) and sodium chloride (NaCl) aerosol particles at 4 m³ h⁻¹ airflow velocity. Therefore, PSA/TPU composite membranes are a promising candidate for high-temperature filtration applications.     

Effect of Solvent on Segregated Network Morphology in Elastomer Composites for Tunable Piezoresistivity

Flexible, light‐weight, and wearable electronics have significant potential for the development of Internet of Things. Flexible sensors with tunable piezoresistive properties are in high demand for various practical applications. Herein, different morphology thermoplastic polyurethane (TPU)/ carbon nanostructure (CNS) composites with segregated network are obtained by swelling the TPU powders using various solvents. The better solvent for TPU, dimethylformamide (DMF), renders the composites with 0.7 wt% CNS stronger polymer‐filler interactions, resulting in significantly improved piezoresistive sensitivity at strain larger than 150%. Also the gauge factors (G_Fs) for these composites are 9.7 in the range 0–60% strain and 19.3 for 60–100% strain. In contrast, the composites with ethanol (EtOH) and tetrahydrofuran (THF) which swell less the TPU show delayed increase in piezoresistivity and G_Fs of 2.2 and 3.5 for strain up to 100%, respectively, suggesting potential applications for stretchable conductors.     

Comparing the compatibility of various functionalized polypropylenes with thermoplastic polyurethane (TPU)

Three functionalized polypropylenes (PP), a maleated PP (PP-g-MA), primary amine functionalized PP (PP-g-NH₂), and secondary amine functionalized PP (PP-g-NHR), were melt blended with a thermoplastic polyurethane (TPU) at different compositions. Compatibility of each functionalized PP with TPU was compared by investigating the binary blends using rheological (mixer torques, dynamic shear rheometry), thermal (dynamic mechanical analysis), mechanical (tensile test), and morphological (scanning electron microscopy with image analysis, particle size analysis) measurements. Compatibility of the three functionalized PP's with TPU is ranked in a decreasing order as follows: PP-g-NHR≥PP-g-NH₂?PP-g-MA, which is attributed to higher reactivity of amine (primary and secondary) with urethane linkages. Accordingly, the TPU blends with the two types of amine functionalized PP's exhibited much better synergy, as reflected by much improved mechanical properties including higher tensile strength and ultimate elongation, and finer and more stable morphologies.     

Modification of thermoplastic polyurethane nanofiber membranes by in situ polydopamine coating for tissue engineering

To improve the interaction between cells and scaffolds, the appropriate surface chemical property is very important for tissue engineering scaffolds. In this work, the dopamine (DA) was first introduced into thermoplastic polyurethane (TPU) matrix to obtain TPU/DA nanofibers by electrospinning. Subsequently, the TPU@polydopamine (PDA) composite nanofibers with core/shell structure were fabricated by in situ polymerization of PDA. In comparison with TPU nanofibers, the uniformization of PDA coating layer on the surface of TPU/DA composite nanofibers significantly increased due to the addition of DA, which used as the active sites to guide the PDA particles accumulated along with the fiber direction. The hydrophilicity and water uptake ability of TPU@PDA composite nanofibers were larger than those of TPU nanofibers. The TPU@PDA composite nanofibers possess excellent comprehensive mechanical properties of high strength, stiffness, elasticity, and recoverability because of the hydrogen bonding occurrence between PDA and DA, as well as between PDA and TPU matrix. The attachment and viability of mouse embryonic osteoblasts cells (MC3T3-E1) cultured on TPU@PDA composite nanofibers were obviously enhanced compared with TPU nanofibers. Those results suggested that the modified TPU@PDA composite nanofibers have superior mechanical and biological properties, which promoting them potentially useful for tissue engineering scaffolds.     

Preparation and characterization of conducting poly(diphenylamine) entrapped polyurethane network electrolyte

Composites of thermoplastic polyurethane (TPU) with poly(diphenylamine) (PDPA) were prepared by entrapping diphenylamine (DPA) molecules into the matrix of TPU and polymerizing DPA within the TPU matrix. Swelling rate of the parent TPU and the composites in 1M LiClO₄ in propylene carbonate solution were compared to understand the influence of the presence of PDPA in the composite in altering the morphology, conductivity, and electrolyte behavior. The nitrogen atoms in the PDPA interact and are likely to form hydrogen bonding with the carbonyl and ether groups in TPU. As a result, different morphology, thermal, and impedance behavior were witnessed for the composites in comparison to TPU. Results from differential scanning calorimetry, scanning electron microscopy (SEM), thermogravimetric analysis, and ac impedance measurements were obtained as supporting evidences. An increase in glass transition temperature for the composite in comparison to TPU infers the increase in phase mixing of soft and hard segment of TPU. The SEM micrograph shows the presence of fibrillar morphology of PDPA molecules in the composite. The ionic conductivity of the swelled composite was 1‐fold higher than that of pure TPU. A schematic representation showing the interaction of PDPA molecules with TPU is presented. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 611–617, 2006     

Blending thermoplastic polyurethanes and poly(ethylene oxide) for composite electrolytes via a mixture design approach

With the aim of obtaining proper composite electrolytes, a systematic modeling analysis for the percentage increase in weight due to swelling with respect to swollen weight, S_w, and the room temperature conductivity (σ₂₅) of the composite films of polyethylene glycol based thermoplastic polyurethane/polytetramethylene glycol based thermoplastic polyurethane/polyethylene oxide [denoted as TPU(PEG)/TPU(PTMG)/PEO] was performed. Using a mixture design approach, empirical models are fitted and plotted as contour diagrams which facilitate revealing the synergistic/antagonistic effects among the mixed polymers. The contour plot results show that both the maximum S_w (64.9%) and the maximum σ₂₅ (72.2 × 10⁻⁵ S cm⁻¹) appear at point X₃ (PEO 85%, TPU(PEG) 15%). The results are reasonably explained from the interactions among polymers on the basis of their molecular structures. The thermal analysis of the composite films is performed to demonstrate the speculations about the interactions among the mixed polymers by using differential scanning calorimeter. The crystallization of PEO spherulites at different compositions was examined by using a polarizing microscope. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 680–692, 2000     

Improvement of polyamide/thermoplastic polyurethane blends with polyamide 6-polyurethane copolymer prepared via suspension polymerization as compatibilizer

The polyamide 6-polyurethane copolymer (PA6-b-PU-b-PA6) was synthesized through anionic suspension polymerization and then mixed with polyamide 6/thermoplastic polyurethane (PA6/TPU) and polyamide 6, 6/thermoplastic polyurethane (PA66/TPU) blends using as the compatibilizer. The results show that the PA6-b-PU-b-PA6 copolymers powders several can be obtained through suspension polymerization using dimethicone as disperse medium. The average diameter of PA6-b-PU-b-PA6 copolymer powders decreased with the increasing of PU content. With the addition of PA6-b-PU-b-PA6, the TPU phase dispersed more uniformly in PA6 or PA66 matrix, and the size of TPU dispersed phase decreased obviously. The PA6-b-PU-b-PA6 copolymer with higher PU content shows better compatibilizing effect. Addition of PA6-b-PU-b-PA6 can improve both strength and toughness of the PA/TPU blends. When the amount of PA6-PU25% copolymer was 5 phr, the tensile strength and notched impact strength of PA6/TPU/PA6-PU25% blends increased 29 and 159.4%, respectively, compared to the PA6/TPU blend without compatibilizer.     

Thermoplastic polyurethane elastomer induced shear piezoelectric coefficient enhancement in bismuth sodium titanate – PVDF composite films

A series of ester-based thermoplastic polyurethane elastomer (TPU) and bismuth sodium titanate polycrystalline oxide (Bi_0.5Na_0.5TiO₃, BNT) co-blended poly (vinylidene fluoride) (PVDF) composite films were prepared. Mechanical test confirms the optimum BNT blending content (25 wt%) and further reveals a linear growth of tensile elongation by increasing TPU content. Microstructure modifications including strengthened hydrogen bond and valence band edge elevation are evidenced to be highly correlated to the dielectric and piezoelectric properties. Significant enhancement (7–13 times) in face shear piezoelectric coefficient (d₃₆) is achieved by adjusting the blending content of TPU. Cross-section image presents a featuring multilayer structure with improved dispersity of BNT particle under a transverse tensile force which effectively increases the interfacial contact area between BNT and polymer blends. This work reveals the significance of band structure modification and anisotropic texture construction on influencing the transfer of piezoelectric charge in TPU blended BNT-PVDF composite film.     

热塑性聚氨酯共混物的增容方法

综述了作为聚氨酯弹性体的一种,热塑性聚氨酯（TPU）与其他聚合物共混改性时,可提高增容性的6种方法（如调整分子链结构、改变共混聚合物的极性、化学改生引入反应性官能团、改变分子极性、加入相容剂、形成互穿网络等）,并提到了对相容性影响很大的共混方法和工艺条件.     

Study on thermoplastic polyurethane/polypropylene (TPU/PP) blend as a blood bag material

Blends with different ratios of thermoplastic polyurethane/polypropylene (TPU/PP) were prepared by melt mixing using an internal Haake mixer. Properties of the blends were investigated using SEM micrographs of cryofractures and measurement of the mechanical strength, water absorption, cell culture, and platelet adhesion in vitro tests, which were compared with those of PVC blood bags. The effect of the addition of the ethylene–vinyl acetate (EVA) copolymer on the TPU/PP blend properties was investigated. The results indicated that a TPU/PP/EVA = 80/20/5 blend can be used as a new blood bag material. It was observed that the blend is homogeneous with higher mechanical strength than that of the commercial PVC blood bag. This blend also showed a compatible cell response in contact with L929 fibroblast cells and fewer tendencies to interaction with platelets compared to the PVC blood bag. Although the blends were immissible and no chemical reaction at the interface could be found, the blood compatibility of the blends were improved. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2496–2501, 2003     

Morphology and mechanical properties of polypropylene/high‐impact polystyrene blends from postconsumer plastic waste

The compatibilizing effect of the triblock copolymer poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene) (SEBS) on the morphological and mechanical properties of virgin and recycled polypropylene (PP)/high‐impact polystyrene (HIPS) blends was studied, with the properties optimized for rigid composite films. The components of the blend were obtained from municipal plastic waste, PP being acquired from mineral water bottles (PP_b) and HIPS from disposable cups. These materials were preground, washed only with water, dried with hot air, and ground again (PP_b) or agglutinated (HIPS). Blends with three different weight ratios of PP_b and HIPS (6:1, 6:2, and 6:3) were prepared, and three different concentrations of SEBS (5, 6, and 7 wt %) were used for investigations of its compatibilizing effect. Scanning electron microscopy showed that SEBS reduced the diameter of dispersed HIPS particles in the globular and fibril shapes and improved the adhesion between the disperse phase and the matrix. However, SEBS interactions with PP_b and HIPS influenced the mechanical properties of the compatibilized PP_b/HIPS/SEBS blends. An adequate composition of PP/HIPS, for both virgin and recycled blends, for applications in composite films with characteristics similar to those of synthetic paper was obtained with a minimal amount of SEBS and a maximal HIPS/PP ratio in the range of concentrations studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2861–2867, 2003     

Effect of Organo-Modified Montmorillonite on the Morphology and Properties of SEBS/TPU Nanocomposites

In this study, novel polystyrene-b-poly(ethylene-butylene)-b-polystyrene (SEBS)/thermoplastic polyurethane (TPU)/organo-modified montmorillonites (OMMT) nanocomposites were prepared by melt mixing. Three different organo-modified montmorillonites, DK2, DK3, and DK4 (listed in descending order of hydrophilicity) were selected. The compatibilizing and reinforcing effects of OMMT on the structure, morphology, thermal stability, mechanical and rheological properties of the SEBS/TPU blends were studied. It was found that the hydrophilic DK2 nanoparticles were largely located in the continuous TPU phase and partially dispersed at the phase interphase, whereas DK3 and DK4 nanoparticles were preferentially located at the phase interface with an intercalated/exfoliated and intercalated structure, respectively. Scanning electron microscopy (SEM) results showed that SEBS/TPU/OMMT nanocomposites exhibited a more densely organized and interconnected structure compared with SEBS/TPU blends. Better thermal property was achieved after adding DK3, with the tensile properties of the SEBS/TPU increased considerably. Rheological analysis revealed that hydrophilic DK2 nanoparticles were more effective in improving rheology properties and showed a more pronounced nonlinear effect. The prepared SEBS/TPU/OMMT nanocomposites displayed desired thermal, mechanical and rheological properties, which are important for many applications. POLYM. ENG. SCI., 60:850–859, 2020. © 2020 Society of Plastics Engineers     

Mechanical properties of glass bead‐ and wollastonite‐filled isotactic‐polypropylene composites modified with thermoplastic elastomers

Mechanical properties of the isotactic‐polypropylene/glass bead (iPP/GB) and iPP/wollastonite (iPP/W) composites modified with thermoplastic elastomers, the poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene) copolymer (SEBS) and corresponding block copolymer grafted with maleic anhydride (SEBS‐g‐MA), were investigated. An increase in toughness of iPP with the elastomers was associated with a decrease in rigidity and strength. Mechanical performance of iPP increased more with acicular W than with spherical GB due to reinforcing effect of W. Comparing the (iPP/GB)/SEBS and (iPP/W)/SEBS composites having the separate microstructure, strength and toughness values of the iPP/GB and iPP/W composites increased more with SEBS‐g‐MA at the expense of rigidity due to the core‐shell microstructure with strong interfacial adhesion. Moreover, the iPP/W composite exhibited superior mechanical performance with 2.5 and 5 vol% of SEBS‐g‐MA because of a positive synergy between the core‐shell microstructure and reinforcing effect of acicular W. The extended models revealed that the elastomer and filler particles in the (iPP/GB)/SEBS and (iPP/W)/SEBS composites acted individually due to the separate microstructure. However, the rigid GB and W particles encapsulated with the thick elastomer interlayer (R₀/R₁ = 0.91) in the (iPP/GB)/SEBS‐g‐MA and (iPP/W)/SEBS‐g‐MA composites acted like neither big elastomer particles nor like individual rigid particles, inferring more complicated failure mechanisms in the core‐shell composites. POLYM. COMPOS., 31:1285–1308, 2010. © 2010 Society of Plastics Engineers     

Influence of Elastomer Modification on Impact Strength of PP/Elastomer/CaCO3 Composite

Polypropylene (PP)/elastomer/fine filler particle ternary composite was prepared using polystyrene-block-poly(ethylene-butene)-block-polystyrene triblock copolymer (SEBS) or carboxylated SEBS (C-SEBS) as elastomer and calcium carbonate (CaCO₃) having mean size about 160 nm as filler. First, SEBS (or C-SEBS) and CaCO₃ particles were mixed to form master batch. Second, the prepared master batch and PP matrix were kneaded. In the PP/SEBS/CaCO₃ ternary composite, CaCO₃ particles and SEBS particles were dispersed in the PP matrix separately. In the PP/C-SEBS/CaCO₃ ternary composite, CaCO₃ particles were encapsulated in C-SEBS and formed a core–shell structure at lower CaCO₃ concentration; however, some CaCO₃ particles were dispersed in PP matrix at higher CaCO₃ concentration. In the PP/SEBS/CaCO₃ composite, the impact strength increased with the amount of incorporated CaCO₃ particles. Whereas, in the PP/C-SEBS/CaCO₃ composite, the impact strength increased with the amount of CaCO₃ particles dispersed in PP matrix. The master-batch method was found to be useful for improving the dispersibility of CaCO₃ particles than the commonly used single-batch method.     

High-performance thermoplastic polyurethane nanocomposites induced by hybrid application of functionalized graphene and carbon nanotubes

A hybrid polymeric system containing carbon nanofillers with different geometrical dimensions is proposed for strategic applications, particularly for electrical properties. Two different carbon nanofillers including functionalized multiwalled carbon nanotubes (fCNTs) and functionalized graphene nanoplatelets (fGnPs) were added to thermoplastic polyurethane (TPU) to prepare single and hybrid nanofiller filled TPU through solution mixing. Sufficient exfoliation of the fGNPs in the single nanocomposites was confirmed by X-ray diffraction, while single filler and hybrid TPU nanocomposites containing fCNTs showed some re-aggregation of these nanofillers. Linear rheology together with scanning electron microscopy revealed a proper exfoliation and dispersion degree for fGnPs and fCNTs, respectively. We have shown that simultaneous addition of fCNTs–fGnPs in the form of a hybrid system into the TPU made a large surface area available and strong interfacial interactions were formed between the hybrid network and the TPU matrix. This in turn led to electrical, thermal and mechanical properties, which were superior to those predicted by the mixture law. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48520.     

Toughening mechanism in polyoxymethylene/thermoplastic polyurethane blends

In order to better understand the toughening mechanism in polyoxymethylene (POM)/thermoplastic polyurethane (TPU) blends and obtain ‘super‐toughened’ POM, we carried out an investigation on the notched impact strength, fractured surface, inter‐particle distance and spherulite size of POM as a function of the TPU content. A compatibilizer, namely polystyrene‐block‐poly(ethylene–butylene)‐block‐polystyrene, grafted with maleic anhydride (SEBS‐graft‐MA), was used to enhance the interfacial interaction between the POM and TPU. The impact strength is found to increase in two steps as a function of TPU content, namely a linear increase at the very beginning, and then a jump of impact strength is seen when the TPU content is larger than 30 wt%. A ‘supertough behavior’ is not observed for POM/TPU blends at room temperature, but can be achieved after adding 5 wt% of SEBS‐graft‐MA as the compatibilizer. The impact strength was found to depend not only on the interparticle distance but also on the interfacial interactions between POM and TPU. The dependence of impact strength on crystal size is considered for the first time, and a single curve is constructed, regardless of the composition and interfacial interactions. Our results indicate that the crystal size of POM indeed plays a role in determining the toughness, and has to be considered when discussing the toughening mechanism. Copyright © 2004 Society of Chemical Industry     

Influence of the incorporation of fine calcium carbonate particles on the impact strength of polypropylene/polystyrene‐block‐poly(ethylene butene)‐block‐polystyrene blends

The Izod impact strength of two kinds of ternary composites was investigated. One consisted of polypropylene (PP), the triblock copolymer polystyrene‐block‐poly(ethylene butene)‐block‐polystyrene (SEBS), and calcium carbonate (CaCO₃) particles, and the other consisted of PP, carboxylated SEBS (C‐SEBS), and CaCO₃ particles. The mean size of the CaCO₃ particles was about 160 nm. According to scanning electron microscopy observations, the composite with SEBS showed a morphology in which SEBS domains and CaCO₃ particles were independently dispersed in the PP matrix. On the other hand, the composite with C‐SEBS showed a morphology in which CaCO₃ particles were encapsulated by C‐SEBS; that is, a core–shell structure was formed. The Izod impact strength of the composite with SEBS was higher than that of the composite with C‐SEBS and the PP/SEBS and PP/C‐SEBS binary blends. According to observations of the fractured surface, the stress‐whitened area was larger in the composite with SEBS than in the composite with C‐SEBS and the PP/SEBS and PP/C‐SEBS binary blends. The toughening mechanism of the composite, using nanometer‐sized CaCO₃ particles in combination with SEBS, was examined. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

热塑性聚氨酯共混改性研究进展

综述了热塑性聚氨酯与聚烯烃、聚苯乙烯、工程塑料(聚碳酸酯、ABS、聚甲醛、苯乙烯一丙烯腈共聚物、聚酰亚胺、聚酰胺等)、环氧树脂、橡胶、短纤维、聚氯乙烯树脂等共混研究进展,共混改性后的材料在某些性能上得到提高或改善,共混的研究为开发新材料提供了新途径,扩大了热塑性聚氨酯的应用。     

Solution blowing of thermoplastic polyurethane nanofibers: A facile method to produce flexible porous materials

Solution blowing (SB) is a promising and scalable approach for the production of nanofibers. Air pressure, solution flow‐rate, and nozzle‐collector distance were determined as effective process parameters, while solution concentration was also reported as a material parameter. Here we performed a parametric study on thermoplastic polyurethane/dimethyl formamide (TPU/DMF) solutions to examine the effect of such parameters on the resultant properties such as fiber diameter, diameter distribution, porosity, and air permeability of the nanofibrous webs. The obtained solution blown thermoplastic polyurethane (TPU) nanofibers had average diameter down to 170 ± 112 nm, which is similar to that observed in electrospinning. However, the production rate per nozzle can be 20 times larger, which is primarily dependent on air pressure and solution flow rate (20 mL/h). Moreover, it was even possible to produce nanofibers polymer concentrations of 20%; however, this increased the average nanofiber diameter. The fibers produced from the TPU/DMF solutions at concentrations of 20% and 10% had average diameters of 671 ± 136 nm and 170 ± 112 nm, respectively. SB can potentially be used for the industrial‐scale production of products such as nanofibrous filters, protective textiles, scaffolds, wound dressings, and battery components. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43025.