Thermoplastic Polyether Ester Elastomer Research Articles

Enhanced Thermal Conductivity in Thermoplastic Polyether Ester Elastomer Vitrimer Composite Foams via Cell Growth-Induced Orientation and Lap of Hybrid Fillers

Lightweight thermal conductive polymer foams own a great potential application in some weight sensitive fields such as aerospace and encapsulation. Herein, the enhancement of thermal conductivity of thermoplastic polyether ester elastomer (TPEE) vitrimer composites foams caused by cell growth inducing fillers orientation and lap was investigated with hybrid fillers of fixed 15 vol.% h-BN and various SiC nanowires. First, the hybrid fillers orientation in TPEE vitrimer composites (TVC) characterized by SEM and XRD patterns showed that the hybrid fillers were induced to be through-plane orientation and no interfacial defects were observed owing to the increasing contact area among fillers caused by large specific area and length of SiC nanowires. Based on that, cells were generated into TVC through scCO2 foaming. The effect of through-plane orientation and lap of hybrid fillers caused by cell growth of different cell structures on the thermal conductivity of TVC foams was investigated using extended Hashin-Shtrikman model and Maxwell-Eucken I model. The results showed that the thermal conductivity of TVC foams could greatly be enhanced to be higher than that of TVC by cell growth of continuous cell structures as it contributed to the through-plane orientation and lap of hybrid fillers to increase the contact and lap ratio among fillers. Thereby, the thermal conductive networks favorable to heat transfer were constructed in TVC foams to enhance the thermal conductivity as well as merit of lightweight.

Compression Property of TPEE-3D Fibrous Material and Its Application in Mattress Structural Layer.

Thermoplastic poly(ether/ester) elastomer (TPEE) has great potential as a mattress material due to its high resilience, breathability, and light weight. This study aimed to evaluate the feasibility of TPEE-3D fibrous material (T3DF), a three-dimensional block material made of TPEE fibers randomly aligned and loop-connected, for mattress application. After testing the compression properties of T3DF, the effects of T3DF structural layers on mattress firmness were investigated. The results showed that T3DF had good energy absorption capacity, broad indentation hardness range (126.94-333.82 N), and high compression deflection coefficient (2.79-4.39). The thickness and density of T3DF were the main factors influencing mattress firmness, and the impact of thickness was more significant (p < 0.05). Owing to the hard and soft segments contained in TPEE, T3DF could be used for both the padding and core layers of the mattress. The hardness value and Dsurface of the mattress with a T3DF padding layer increased with T3DF density but decreased with T3DF thickness. Moreover, the hardness value and Dsurface of the mattress with a T3DF core layer increased with T3DF density, while with T3DF thickness, its Dsurface increased and Dbottom decreased. Therefore, the thick and low-density T3DF padding layer could improve the comfort of the mattress surface, a thin T3DF core layer could satisfy both the softer surface and the firmer bottom of the mattress.

Effects of Recycled Polymer on Melt Viscosity and Crystallization Temperature of Polyester Elastomer Blends.

As the world is paying attention to the seriousness of environmental pollution, the need for a resource circulation economy is emerging due to the development of eco-friendly industrial groups. In particular, the recycling of thermoplastic elastomers without cross-link has been highlighted in the plastics field, which has rapidly developed the industry. Growing interests have been directed towards the advancement of thermoplastic polyether-ester elastomer (TPEE) as a material suitable for the circular economy owing to its remarkable recyclability, both in terms of mechanical and chemical processes. Due to its excellent processability, simple mechanical recycling is easy, which is a driving force towards achieving price competitiveness in the process. In molding TPEE resin, it is essential to check the thermal properties of the resin itself because the thermal properties, including the melting and crystallization temperatures of the resin, depend on the design of the polymer. In this study, the thermal and mechanical performances of TPEE blends were evaluated by manufacturing compounds by changing the amount of recycled resin and additives. When the recycled resin was added, the melt flow index (MFI) changed rapidly as the temperature of the melt flow index measurement increased. Rapid changes in MFI make the fiber spinning process uncontrollable and must be controlled by optimizing the addition of compatibilizers. Based on the thermal property results, compatibilizers such as Lotader and Elvaloy series exhibited minimal change in glass transition temperature, even with greater amounts added. This makes them well-suited as compatibilizers for fiber spinning.

Rational design for the development of thermoplastic poly(ether-ester) elastomers from bio-based 2,5-furandicarboxylic acid with high elasticity

Development of bio-based thermoplastic poly(ether-ester) elastomer (TPEE) with high performance similar to commercial and petroleum-based TPEE is of great interesting nowadays. Herein, by considering both the hard and soft segments, a rational design strategy is proposed for the synthesis of bio-based TPEE with high elasticity based on a bio-based aromatic monomer 2,5-furandicarboxylic acid (FDCA). The hard segment is poly(neopentyl glycol 2,5-furandicarboxylate) (PNF), a FDCA-based polyester with both high melting temperature and crystallization ability. While the soft segment is poly(tetramethylene glycol) (PTMG), which is widely used for the synthesis of TPEE. By adjusting the molecular weight (Mn) of PTMG soft segment from 650 to 2900 g/mol and its content from 50 to 70 wt%, a series of bio-based TPEEs with excellent performance were synthesized. Our preliminary study of PNF-PTMG multiblock copolymers has shown that the elastic recovery rate is outstanding. The initial elastic recovery ratio at 200 % strain can approach 80 % when the Mn of PTMG is 2000 g/mol and the wt.% of PTMG was 70 %, which is significantly higher than those of the commercial TPEEs. PNF-PTMG displays increasing thermal resistance with Tm up to 194 °C with the increasing of soft segment length. This study suggests a feasible solution for the preparation of bio-based TPEE with ideal performance.

The influence of dynamic crosslinked topology and bond exchange on thermal properties, viscoelasticity, and foaming behavior of multibranched TPEE vitrimer

Thermoplastic polyester ether elastomer (TPEE) vitrimers with different dynamic crosslinked networks were synthesized via zinc (II) acetylacetonate-catalyzed epoxy chemistry. The effects of bond exchange within networks, characterized by number of catalytic centers per crosslink (CC), and the dynamic crosslinked topology, characterized by number of entanglement and crosslinking points per crosslink (EC), on thermal, rheological, and foaming properties of TPEE vitrimer were compared. The results show that increasing EC is more favorable for lower crystallization temperature than improving bond exchange owing to the bad structural symmetry but almost constant crystallinity owing to the branches. TPEE vitrimer with a complex dynamic crosslinked topology exhibited slow relaxation with a stronger relaxing response and steeper strain hardening than that with more bond exchanges, indicating better viscoelasticity. Moreover, the good foaming behavior of TPEE vitrimers was ascribed to the dynamic crosslinked networks, which promoted heterogeneous nucleation to increase the cell density, and strain hardening good for cell growth as it suppressed cell coalescence and rupture. Furthermore, increasing CC facilitates bond exchange, promoting more uniform heterogeneous nucleation and cell size dispersity than those afforded by a complex dynamic crosslinked topology achieved by increasing EC. The improvement of foaming behavior for TPEE vitrimer is quite different from that of branched polymer by enhancing cell growth rather than cell density.

Effects of thermoplastic poly(ether-ester) elastomer and bentonite on properties of recycled poly(ethylene terephthalate)

The synergistic effects of thermoplastic poly(ether-ester) elastomer (TPEE) and bentonite nanoclay on mechanical, morphological, thermal, and dynamic mechanical properties of recycled poly(ethylene terephthalate) (R-PET) were investigated. The efficiency of TPEE as impact modifier for the R-PET was evidenced by a significant increase in the impact strength and elongation at break with increasing TPEE contents (from 10 to 30 wt%), while the tensile strength and Young’s modulus exhibited an opposite trend. The 70/30 (wt%/wt%) R-PET/TPEE blend was selected as an optimum formulation for further blending with a very low loading of bentonite (1−5 parts per hundred of resin, phr) using the same processing techniques (extruding and injection molding). X-ray diffraction and transmission electron microscopy revealed that the 1 phr bentonite nanocomposite exhibited an exfoliated structure with the highest improvement in the mechanical properties compared with other nanocomposites and the unfilled blend. Meanwhile, the nanocomposites with 2, 3, and 5 phr bentonite formed tactoid or agglomerated bentonite morphology. Differential scanning calorimetry, thermogravimetric and dynamic mechanical analyses demonstrated a noticeable increase in the crystallization temperature, a comparable thermal stability, and a slight increase in the glass transition temperature, respectively, of all nanocomposites when compared with those of the neat R-PET.

Development of thermoplastic polyether ester elastomer microcellular foam with high resilience: Effect of chain extension on foaming behavior and mechanical properties

AbstractThe lightweight development of thermoplastic polyether ester elastomer (TPEE) has been limited by its low‐melt strength. In this work, the epoxy chain extender ADR was employed to improve TPEE's melt strength in order to enhance its foamability by supercritical N2 (sc‐N2). The results showed that the melt strength of TPEE increased gradually with the increase of ADR content, which led to the uniformity of the foam cell structure and the improvement of its mechanical properties, that is, a high resilience of 82%. However, when ADR content exceeded 1.6 phr, the viscosity was too high to induce foaming. Remarkably, the maximum stress retention of TPEE foam with 1.6 phr ADR remained at 90% after 50 cycles of compression, while the strain recovery rate was higher than 85%. The prepared TPEE foam has excellent resilience and dynamic mechanical properties, which broadens its application in fields of midsole, sports equipment and transportation.

A shape-memory, room-temperature flexible phase change material based on PA/TPEE/EG for battery thermal management

The development of conventional battery thermal management (BTM) based on phase change material (PCM) is restricted by its low thermal conductivity, leakage and high rigidity. To solve these problems, the thermally induced flexible phase change materials (FPCMs) have been proposed, but their flexibility only manifests at temperatures above the phase change temperature, which is detrimental to the assembly at room temperature. Herein, using paraffin (PA) as PCM, thermoplastic polyether ester elastomer (TPEE) as flexible support material and expanded graphite (EG) as heat transfer enhancement material, a novel FPCM with shape memory property and wider flexible temperature (−15 to 60 °C) was successfully prepared through melt-mixing method. And then it was skillfully assembled on power batteries at room temperature through flexibility in conjunction with shape memory property. On this basis, the flexibility of FPCM can be utilized to reduce thermal contact resistance during the whole process of battery operation. The results revealed that the measured thermal contact resistance of the above BTM was 0.272 °C/W, lower than that of previous thermally induced FPCM reported. Furthermore, the maximum temperature of the battery module with the passive BTM based on FPCM could be maintained below 55 °C and the temperature difference was within 3 °C under the high discharge rate of 5C and 40 °C ambient temperature.

Synthesis of bio-based poly(ester-ether) elastomers from 2,5-furandicarboxylic acid (FDCA) with excellent thermo-mechanical properties

As a novel polyester possessing high melting temperature and well crystallization ability, poly(1,4-cyclohexanedimethylene furandicarboxylate) (PCF), produced from bio-based 2,5-furandicarboxylic acid and 1, 4-cyclohexanedimethanol, could be used as promising hard segment to develop new bio-based thermoplastic poly(ether-ester) elastomer (TPEE). Multiblock poly(ether-ester)s based on PCF, with molecular weight (Mn) of soft segments poly(tetramethylene glycol) (PTMG) ranging from 250 to 2900 g/mol while maintaining the weight fraction at 70%, were synthesized to investigate the effects of soft segments length on microphase structure and thermodynamic properties of copolymers. The results show that the increase in Mn of the soft segment promotes the microphase separation of the copolymers. Macroscopically, copolymers have excellent comprehensive properties. Tm was promoted from 126.0 to 228.7 °C, and Td,5% was higher than 320 °C. The tensile strength and modulus of resulting copolymers were within the range of 14–26 MPa and 29–53 MPa, respectively, with elongation at break exceeding 550%. The copolymer exhibited elastic recovery ratio of 75.5% at 200% strain when the Mn of PTMG unit was 2000 g/mol. This work introduces a new bio-based TPEE and enriches a detailed understanding of the impact of soft segments length on the structural properties of TPEE, which is fundamental to design tailor-made TPEE with desired properties.

Mechanical and rheological properties and CO2-foaming behavior of reactively modified TPEE with controlled chain entanglement

Thermoplastic polyether ester elastomer (TPEE) foams can be fabricated using supercritical carbon dioxide (CO2) as an environment-friendly blowing agent. In this study, we investigated the effect of chain entanglement on the mechanical properties, viscoelasticity, and CO2-foaming behavior of TPEE. A series of branched TPEE samples with controlled chain entanglement were prepared by reactive extrusion using modifiers with epoxy groups. The gel-permeation chromatography–intrinsic viscosity (GPC-IV) methodology was employed to determine branch density. The junction point of chain entanglement was obtained; it increased at higher branch densities. The tensile behavior revealed that the branched TPEE samples became more rigid and poorer ductility, with stronger chain entanglement. Small-amplitude oscillation rheology showed enhanced shear thinning and zero-shear viscosity, reduced loss factor, and slower relaxation; these parameters indicated an improvement in linear viscoelasticity. Furthermore, nonlinear viscoelasticity was studied using elongational rheology, and the results were analyzed in combination with molecular stress function (MSF) model. The experimental results revealed that strain hardening was steeper with stronger chain entanglement, as proved by increasing value of free parameters fmax2 and β from MSF model. The reactively modified TPEE samples exhibited a larger expansion ratio than that of raw TPEE during the CO2-foaming process. Additionally, broader foaming temperature window to fabricate high-fold TPEE foams at CO2-foaming process enable the reactively modified TPEE to be used in the industrial production of TPEE foam with stable quality like bead and molded foaming.

Role of formulation additives on the properties of thermoplastic polyether ester elastomer-based and carbon fabric-reinforced multilayer composites

In this study, multilayer carbon fabric-reinforced composites (CFRC) were manufactured by compression molding technique with the combination of carbon fabric and thermoplastic polyether ester elastomer (TPEE) composites. The TPEE-based polymer layers were prepared as binary, ternary, and quaternary composites using carbon black (CB) or N-(β-aminoethyl)-γ-aminopropyl-trimethoxysilane (AEAP) modified carbon black (mCB), ethylene-glycidyl methacrylate copolymer (EGMA) and/or paraffin oil. The effects of formulation additives on multilayer CFRC were investigated in terms of their mechanical, electrical resistivity, electrically stimulated shape memory properties and morphologies. Tensile modulus of neat TPEE included multilayer CFRC increased slightly with the addition of both mCB and oil to TPEE. The highest impact strength of 112.2 kJ/m2 was obtained for TPEE-mCB-EGMA-Oil containing CFRC multilayer composites, which was 30% higher than CFRC with neat TPEE. All modified and reinforced CFRC exhibited higher electrical conductivities than neat TPEE containing CFRC. Electrically triggered bending test showed that combination of TPEE, mCB, EGMA and oil together with carbon fabric in multilayer structure revealed 80% shape recovery ratio within less than 2 min.

An experimental study on the torsional stiffness and limit torque of a jaw coupling with consideration of spacer's hardness and installation methods

Abstract The jaw coupling with a flexible spacer is frequently used in the torque transmission between shafts with misalignment for machinery. Its torsional stiffness and limit torque closely determine the operational capacity and the dynamic characteristics of the system because the coupling is usually the most flexible link in the driving chain. In this study, the optimal design of a jaw coupling with an elastomeric spacer was investigated using the Taguchi method by considering four design factors: the tightening method of the clamping bolts, the tightening torque of the clamping bolts, the hardness of the thermoplastic polyether ester elastomer spacer and the installation angle between the two end blocks of the coupling. All specimens were tested by using an in-house torsion tester to record the torque-angular deformation responses. The results showed good reliability and repeatability, with a coefficient of variance within 5%. Spacer's hardness was found to be the most significant factor regarding the torsional stiffness, while the magnitude of the clamping torque had the most critical role in the limit torque. The estimation formulae for the torsional stiffness and limit torque of the jaw coupling were obtained by using the statistical regression of the measured data, respectively. Both formulae predicted the performance of the optimal designs within 5% of error compared to the confirmation tests.

Evolution of cell morphology from sub-macroscale to nanoscale in modified thermoplastic polyether ester elastomer via supercritical CO2 foaming

Modified thermoplastic polyether ester elastomer (TPEE) foams with the cell size from sub-macroscale to nanoscale were prepared by solid-phase batch foaming in the presence of supercritical CO2 (scCO2). Multifunctional epoxy chain extender (CE) with the functionality of 9 was incorporated into TPEE to form a moderate crosslinking structure. The rheological property and crystallization behavior of modified TPEE were investigated, and then the cell morphologies of as-prepared TPEE foams were analyzed. It was found that the introduction of branching and crosslinking structure led to an increased melt viscosity and a reduction of crystallinity of TPEE. Moreover, it was identified that the rheological property dominated the foamability at high foaming temperature of 185 °C, and then the fine sub-macroscale cells were seen. Conversely, the change of crystallization behavior mainly affected the evolution of cell morphology at low foaming temperature of 160 °C, and the foams with nano and/or micro cells are obtained. As a result, a series of TPEE foams with the cell morphology from sub-macroscale to nanoscale could be achieved by adjusting the crosslinking degree of modified TPEE and the temperature of supercritical CO2 foaming.

Effects of thermoplastic poly(ether‐ester) elastomer and bentonite nanoclay on properties of poly(lactic acid)

AbstractThis work presented the influence of thermoplastic poly(ether‐ester) elastomer (TPEE) and bentonite (BTN) on improving the mechanical and thermal properties of poly(lactic acid) (PLA). PLA was initially melt mixed with TPEE at six different loadings (5–30 wt%) on a twin screw extruder and then injection molded. The mechanical tests revealed an increasing impact strength and elongation at break with increasing TPEE loading, but a diminishing Young's modulus and tensile strength with respect to pure PLA. The blend at 30 wt% TPEE provided the optimum improvement in toughness, exhibiting an increase in the impact strength and elongation at break by 3.21‐ and 10.62‐fold over those of the pure PLA, respectively. Scanning electron microscopy analysis illustrated a ductile fractured surface of the blends with the small dispersed TPEE domains in PLA matrix, indicating their immiscibility. The 70/30 (wt/wt) PLA/TPEE blend was subsequently filled with three loadings of BTN (1, 3, and 5 parts by weight per hundred of blend resin [phr]), where the impact strength, Young's modulus, tensile strength and thermal stability of all the blends were improved, while the elongation at break was deteriorated. Among the three nanocomposites, that with 1 phr BTN formed exfoliated structure and so exhibited the highest impact strength, elongation at break, and tensile strength compared to the other intercalated nanocomposites. Moreover, the addition of BTN was found to increase the thermal stability of the neat PLA/TPEE blend due to the barrier properties and high thermal stability of BTN.

Improving the Continuous Microcellular Extrusion Foaming Ability with Supercritical CO2 of Thermoplastic Polyether Ester Elastomer through In-Situ Fibrillation of Polytetrafluoroethylene.

In-situ fibrillated polytetrafluoroethylene (PTFE) enhanced nanocomposites were successfully prepared by mixing thermoplastic polyether ester elastomer (TPEE) and PTFE using a twin-screw extruder. Well-dispersed, long aspect ratio PTFE nanofibrils with a diameter of less than 200 nm were generated and interwoven into networks. Differential scanning calorimetry and in-situ polarized optical microscopy showed that the PTFE nanofibrils can greatly accelerate and promote crystallization of the TPEE matrix and the crystallization temperature can be increased by 6 °C. Both shearing and elongational rheometry results confirmed that the introduction of PTFE nanofibrils can significantly improve the rheological properties. The remarkable changes in the strain-hardening effect and the melt viscoelastic response, as well as the promoted crystallization, led to substantially improved foaming behavior in the continuous extrusion process using supercritical CO2 as the blowing agent. The existing PTFE nanofibrils dramatically decreased the cell diameter and increased cell density, together with a higher expansion ratio and more uniform cell structure. The sample with 5% PTFE fibrils showed the best foaming ability, with an average diameter of 10.4–14.7 μm, an expansion ratio of 9.5–12.3 and a cell density of 6.6 × 107–8.6 × 107 cells/cm3.

A novel blend material to improve the crystallization and mechanical properties of poly (ethylene terephthalate)

To resolve the problems of phase separation in the process of toughness improvement for poly (ethylene terephthalate) (PET) by blending rubber phase, referencing the technology of interpenetrating polymer network (IPN) hindering phase separation, here a solution of phase separation restraining was developed in the process of adding thermoplastic polyester-ether elastomer (TPEE) to improve the toughness of PET by using nucleation agent bicyclo[2.2.1]heptane-2,3-dicarboxylic acid disodium salt (HPN-68 L) to enhance greatly gelation temperature to hinder the melt movement under the high temperature. It was found that TPEE and HPN-68 L could improve the crystallization rate and toughness of PET at the same time. The long period of PET increased after adding HPN-68 L and TPEE, while the crystal form of PET had a negligible effect. In addition, the spherulites arranged more closely and the size was more uniform after adding the nucleator HPN-68 L into PET/TPEE blends. In mechanical properties testing, with increasing the TPEE content, the flexural strength and flexural modulus of PET/TPEE/HPN-68 L blends were decreased, but the toughness of the blends was greatly improved. Especially, no distinct phase separation was observed and the tissue morphology of the blends was very uniform.

Synergistic effects between a triazine-based charring agent and aluminum phosphinate on the intumescent flame retardance of thermoplastic polyether ester

The triazine-based charring agent (CFA) with perfect charring ability was synthesized and characterized. The synergistic effects between CFA and aluminum phosphinate (AlPi) on flame retardancy, thermal degradation, and flammability properties of thermoplastic polyester-ether elastomer (TPEE) were investigated by limiting oxygen index (LOI), vertical burning test (UL-94), cone calorimeter test (CCT), thermogravimetric analysis (TGA), laser Raman spectroscopy (LSR) and scanning electron microscopy (SEM). The results from UL-94 test showed that, by compounding 14 wt% AlPi and 4 wt% CFA with TPEE, the LOI value reached 28.5% and the UL-94 rating reached V-0 (1.6 mm). TGA results indicated that there is good synergistic charring ability between CFA and AlPi, especially the increased residues at high temperature (T > 700 °C). The CCT test results showed that CFA could change the combustion behavior of TPEE and effectively accelerate the formation of expanded carbon layers. The residues after combustion were measured by LRS and SEM, demonstrating that CFA can promote the formation of dense and stable carbon layers during the combustion, which could inhibit the melt dropping and improve the fire retardancy of TPEE composites. Thus, CFA was a promising synergistic agent in halogen-free flame retardant TPEE.

Effect of chain topological structure on the crystallization, rheological behavior and foamability of TPEE using supercritical CO2 as a blowing agent

Thermoplastic polyether ester elastomer (TPEE) has been reacted with different multi-functional group modifiers, such as 2,2′-bis(2-oxazoline) (2,2′-BOZ) and triglycidyl isocyanurate (TGIC), to create long chain TPEE and highly branched TPEE respectively by reactive processing. Both chain extension and branching processes could improve the complex viscosity and modulus, but TPEE with a branched structure showed distinguished strain-hardening behavior. The branched structure can also accelerate crystallization processes. In the foaming process, TPEE with branched chains have a higher expansion ratio, higher cell density and wider foaming window when compared with TPEE with long chains. The branched structure can prevent cells from collapsing to obtain foamed TPEE with high expansion ratios ranging from 1.5 folds to 16 folds, cell diameters ranging from 3 μm to 13 μm and a cell density between 3.6×108 cells/cm3 and 7.1×109 cells/cm3.

Effect of hydrolytic degradation on the mechanical property of a thermoplastic polyether ester elastomer

Polymers with a finite lifetime are of great interest for oil and gas industry. Thermoplastic elastomers (TPEs) combine the strength of thermoplastics with the flexibility of elastomers, a characteristic also potentially useful in oil and gas applications. We studied the hydrolytic degradation of a TPE of interest at elevated temperatures from both a mechanical and chemical perspective, and have demonstrated that the chemical degradation rates, the change in crystallinity and the storage modulus all follow the pseudo zero order kinetics with respect to varying time at three temperatures. Applying Arrhenius' empirical relationship to the determined rates gives rise to a temperature-dependent model that predicts the degradation behavior of the TPE outside of the experimental temperature range. Our results indicate that hydrolytic degradation leads to an increase of crystallinity (chemicrystallization) and a decrease of tensile strength and strain, and that the increase of crystallinity strongly correlates to the increase of the storage modulus. The polymer eventually deteriorates due to brittleness.

Poly(neopentyl glycol 2,5-furandicarboxylate): A Promising Hard Segment for the Development of Bio-based Thermoplastic Poly(ether-ester) Elastomer with High Performance

With a high melting temperature and good crystallization ability, poly(neopentyl glycol 2,5-furandicarboxylate) (PNF), a polyester derived from bio-based 2,5-furandicarboxylic acid and neopentyl glycol, has been proposed and proved to be a promising hard segment for the development of novel bio-based thermoplastic poly(ether-ester) elastomer (TPEE). The resulting TPEE, namely PNF–PTMG, has high performance comparable to the petroleum-based counterpart PBT–PTMG (i.e., Hytrel, Dupont). Among all of the existing polyesters derived from bio-based 2,5-furandicarboxylic acid (FDCA), PNF has perfectly balanced properties, namely, a high melting temperature of 200 °C and a good crystallization ability to easily grow medium to large-size crystalline spherulites. Characterizations based on dynamic mechanical analysis and small-angle X-ray scattering suggest that there are two domains in PNF–PTMG, the crystalline PNF and a mixture of amorphous PNF and PTMG. These two domains form microphase separation induced mainly...