Poly Ether Ester Research Articles

Enhancing Mechanical Performance of High-Density Polyethylene at Different Environmental Conditions with Outstanding Foamability through In-Situ Rubber Nanofibrillation: Exploring the Impact of Interface Modification.

In this study, we utilized in situ nanofibrillation of thermoplastic polyester ether elastomer (TPEE) within a high-density polyethylene (HDPE) matrix to enhance the rheological properties, foamability, and mechanical characteristics of the HDPE nanocomposite at both room and subzero temperatures. Due to the inherent polarity differences between these two components, TPEE is thermodynamically incompatible with the nonpolar HDPE. To address this compatibility issue, we employed a compatibilizer, styrene/ethylene-butylene/styrene copolymer-grafted maleic anhydride (SEBS-g-MA), to reduce the interfacial tension between the two blend components. In the initial step, we prepared a 10% masterbatch of HDPE/TPEE with and without the compatibilizer using a twin-screw extruder. Subsequently, we processed the 10% masterbatch further through spun bonding to create fiber-in-fiber composites. Scanning electron microscopy (SEM) analysis revealed a significant reduction in the spherical size of HDPE/TPEE particles following the inclusion of SEBS-g-MA, as well as a much smaller TPEE nanofiber size (approximately 60-70 nm for 5% TPEE). Moreover, extensional rheological testing revealed a notable enhancement in extensional rheological properties, with strain-hardening behavior being more pronounced in the compatibilized nanofibrillar composites compared to the noncompatibilized ones. SEM images of the foam structures depicted substantial improvement in the foamability of HDPE in terms of the cell size and density following the nanofibrillation process and the use of the compatibilizer. Ultimately, the in situ rubber fibrillation and enhancement of HDPE and TPEE interface using a compatibilizer led to increasing the HDPE ductility at room and subzero temperatures while maintaining its stiffness.

Effect of Dicarboxylic Acid Chain Length on the Tribological Properties of Aqueous Polyether Esters

ABSTRACTThis article presents the preparation of environmentally friendly water‐soluble lubricant additives. Adipic acid (AA), sebacic acid (SA) and dodecanedioic acid (DA) were individually subjected to esterification reactions with polyethylene glycol 1500 (PEG1500) to prepare a class of water‐soluble polyether esters (AAPEE1500, SAPEE1500 and DAPEE1500) (referred to as XAPEE1500s) that exhibit excellent water solubility and do not contain environmentally harmful elements. First, the molecular structure characterisation and functional group analysis of these additives will be conducted using an infrared spectrometer and a nuclear magnetic resonance spectrometer. Subsequently, the frictional properties of the additives in the base liquid (deionised water) will be investigated using an SRV‐V tribometer, Falex pin‐on‐disc tribometer and screw torque tester. The surface morphology of wear scars will be characterised and analysed using scanning electron microscopy (SEM) and a non‐contact 3D profilometer. Finally, the lubrication mechanism of the DAPEE1500 additive will be analysed using X‐ray photoelectron spectroscopy (XPS). The results indicate that the optimal lubrication performance is achieved when the added mass fraction of DAPEE1500 is at 3%. Compared with 0.5 wt% DAPEE1500, the average friction coefficient of 3 wt% DAPEE1500 decreased from 0.285 to 0.122, and the wear volume decreased from 25.52 × 10−5 μm3 to 10.96 × 10−5 μm3. The lubrication mechanism of polyether ester is the result of the combined action of its polar ester functional groups and long carboxylic acid chains in the structure. These polar functional groups can form a relatively firm adsorption film on the friction surface, while the long carboxylic acid chains act as a brush‐like isolating layer, thus demonstrating superior anti‐wear and anti‐friction performance.

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.

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.

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.

Reverse thermo-responsive biodegradable shape memory-displaying polymers

This study introduces shape memory-displaying (SM), reverse thermo-responsive (RTR) biodegradable polymers consisting of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblocks, and polycaprolactone (PCL) segments. The interplay between their composition, morphology and mechanical properties and their SM and RTR behavior was investigated as the polymers degraded. HO-(CL)n-(PEO-PPO-PEO)-(CL)n-OH pentablocks were synthesized and chain extended using hexamethylene diisocyanate (HDI), whereby a range of PFCLn polyether ester urethanes were generated.The PCL blocks formed two different crystalline phases melting at different temperatures, one acting as the net-points and the other as the switching segments.PFCLn polymers displayed remarkable SM behavior, as revealed by their high Rf and Rr values, and RTR behavior, as demonstrated by the significantly higher water uptake levels they attained below their LCST as opposed to above the transition.The polymers retained their RTR behavior as they degraded over the period investigated, while a gradual enrichment in the PCL content was observed as degradation took place. PFCLn polymers retained their excellent SM properties throughout fifteen SM full cycles conducted over two months.The dual SM/RTR functionality of the polymers developed render them especially suitable for a diversity of applications, such as in drug delivery, robotics and sensors.

Resin transfer in oil-water interface intensified by H2O2 and demulsifier for efficient water separation in tight oil

Tight oil is an important unconventional oil resource, but it is difficult to separate oil and water from produced liquid and make efficient use of it. Due to the stable structure of oil–water interface caused by resin, it is difficult to achieve demulsification. In this work, a series of polyether ester demulsifierswith different degree of polymerization were designed by esterification and polymerization. In addition, hydrogen peroxide was used to regulate the structure of resin to enhance the transmission of polyether ester, and the replacement of resin was strengthened through the structural design of polyether ester. The results showed that the molecular weight and dipole moment of resin oxidized by hydrogen peroxide decreased, which was beneficial to the transfer of demulsifier. With the increase of polymerization degree, the oil solubility and surface activity of polyether ester were improved, and the replacement ability of resin was strengthened·H2O2 and demulsifier were used to synergistically promote demulsification, the dehydration rate could be further increased to 99.2%, and the water content in tight oil could be reduced to 0.56%.

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.

Highly Stretchable and Sensitive Single-Walled Carbon Nanotube-Based Sensor Decorated on a Polyether Ester Urethane Substrate by a Low Hydrothermal Process.

We report a highly stretchable sensor with low-concentration (1.5 wt %) single-walled carbon nanotubes (SWCNTs) on flexible polyether ester urethane (PEEU) yarn, fabricated using a low hydrothermal process at 90 °C. Although SWCNTs restrict the PEEU polymer chain mobility, the resulting ductility of our nanocomposites reduces only by 16.5% on average, initially from 667.3% elongation at break to 557.2%. The resulting electrical resistivity of our nanocomposites can be controlled systematically by the number of hydrothermal cycles. A high gauge factor value of 4.84 is achieved at a tensile strain below 100%, and it increases up to 28.5 with applying a tensile strain above 450%. We find that the piezoresistivity of our nanocomposite is sensitive to temperature variations of 25–85 °C due to the hopping effect, which promotes more charge transport at elevated temperatures. Our nanocomposites offer both a high sensitivity and a large strain sensing range, which is achieved with a relatively simple fabrication technique and low concentration of SWCNTs.

СИНТЕЗ ФОСФОРОВМІСНИХ ПСЕВДОПОЛІАМІНОКИСЛОТ ПОЛІЕСТЕРНОГО ТИПУ

The method of obtaining phosphorus-containing polyester by the Steglich reaction is considered. The results of studies on the production of polyesteresters using ethyl phosphate group in the structure of dipolyethyleneglycolethylphosphate are presented. The obtained polymer was characterized by IR and 1H NMR spectroscopy. The composition of polyester ether was evaluated and its end groups were analyzed.

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.

ANALYSIS OF MODERN DEVELOPMENTS OF POLYMERIC MATERIALS WITH THE SPECIFIC TECHNICAL AND TECHNOLOGICAL CHARACTERISTICS

The article considers the characteristics of common composite materials. The following have been used for industrial use: carbon plastics – composites based on high-strength carbon fibers, organometallic plastics – allora, thermoplastics – polyester ether ketone and polyphenylene sulfide, fiberglass. By structure, composites are divided into several classes: fibrous, layered, dispersed, compacted and nanocomposites. The main advantage of any composite material is that it can be given the specific technical and technological characteristics. Due to changes in the composition, structure, size of reinforcing elements and technology of materials, the properties of composites can vary widely, from soft, plastic to hard, brittle. The strength of the material depends on the geometric characteristics of the fibers, the greater the ratio of length to diameter, the stronger it is. It is the size of the reinforcing elements that determines the direction of use of the composite, they affect the rheological and structural and mechanical properties of the material. The designed properties determine the reliability of the structure, which is important when using these materials in the development of military, aerospace equipment, weapons.The introduction of innovative technologies for the formation of products from composite materials has simplified the production process and obtained dimensional monolithic structures. This contributed to their introduction in the field of shipbuilding, in particular, in the construction and modernization of submarines, ships and boats. Composite materials, in addition to elements of superstructures and fairings of acoustic antennae, are used to make rudders, stabilizers, propellers, fragments of shaft lines, rocket shafts, fairings for lifting mast devices, compressed air storage tanks, constructions of separate ship warfare and technical means, etc.

Demulsification of produced fluid from heavy crude oil by novel multifunctional polyether ester

ABSTRACT Novel high-efficient demulsifiers QFB with anionic group and QFC with anionic and cationic group were synthesized by esterification-polymerization method from polyether BH-72 for the demulsification of ASP flooding produced fluid from heavy crude oil in offshore oilfields in this paper. The demulsification effect of BH-72, QFB, and QFC was investigated by Analyzer of Concentrated Liquid Dispersions and QFC had the best demulsification performance. The optimal dehydration rate of produced fluid can reach 95.3% with 80 mg/L QFC after settling for 30 min at 60°C under ultrasonic enhancement.

Tensile deformation and morphology changes in segmented elastomer films and fibers including mechanical property modeling

AbstractSegmented polyether soft segment (SS) elastomers with different hard segments (HS) in film and fiber form were studied by birefringence, DSC, and tensile tests. To understand the morphological contributions to property differences, high resolution tapping AFM resolved ribbon‐like highly anisotropic hard domain (HD) lamellae in low modulus Pebax (polyamide 12 HS) and polyetherester (PEE), films, while lower HS content high melting poly(urethane urea) (PUU) had much smaller less anisotropic but higher melting HDs, explaining its enhanced thermal and mechanical hysteresis properties. Stress–strain tensile data demonstrate the excellent strength and toughness of PUUs and some spun PEE fibers, and film and fiber birefringence data applied during strain cycling up to very high stresses provided the molecular basis for the varying properties. The parameters from non‐Gaussian fits of tensile data provide insight into network properties for these systems exhibiting very high strengths and a large degree of strain hardening. Modeling of PEE and Pebax films also shows the effects of substantial plastic yielding of the HD networks. Tensile data were obtained as a function of strain rate and temperature to help understand the contributions of network restructuring and other factors. For fibers, strain rate data spanning seven decades show and unusual drop in strengths at very high strain rates. Temperature‐dependent tensile data also show large differences between PUU materials versus lower melting PEEs.

Synthesis and characterization of flame retardant polyurethane: Effect of castor oil polyurethane on its properties

A Flame retardant polyether ester urethane was produced using PPG, phosphorous, phthalic anhydride, and isophorone diisocyanate. For the formulation of polymer blend (PBs), bio-based polyurethane was procured from castor oil (CPU) and was blended with polyether ester urethane (PEEU). The different characterizations were done to determine the effect of bio based polyurethane on the properties of PEEU. The comparative studies show PBs have better properties compared to flame retardant PEEU. The thermal degradation study shows a 30–40% decrease in the rate of thermal degradation in PBs. LOI values of PBs have been decreased by 2–3%. The mechanical properties show that the breaking elongation of PBs has increased with 50–90%, but on the other hand, tensile strength has been decreased from 3 (MPa) to 5 (MPa). The gel content in PBs has increased with 10–20%. The hydrolytic stability and contact angle of PBs have been increased with an increase in the CPU ratio. Soil burial test results show that increasing the ratio of CPU in PBs lowers the rate of bacterial attack on the polymeric chain.

Effect of increasing NCO ratio on properties of flame retardant di-phosphorous based polyether ester urethanes

Flame retardant polyether ester urethanes have been synthesized by reacting di phosphorous based polyether ester polyol with IPDI and HDI. Four sets of polyurethanes were prepared using two different NCO molar ratios. Physico-chemical properties of polyols and polyurethanes were measured. Instrumental techniques like FTIR, GPC, and NMR were used for the characterization of the polymers. LOI and UL-94 were used to determine the flame retardant properties of polyurethane films. The morphological study was done using SEM which reveals that an increase in NCO ratio increases microphase separation in polyurethanes. The thermal and mechanical properties of polyurethanes were determined using instrumental analysis. Chemical resistance properties of coated films were studied using acid and alkali and ionized water.

Studies on Biodegradable Polyether Ester Urethanes from Natural Resource and their Application in Coatings

Polyether ester urethanes from natural resources have wide range of applications in coating and paint industries. Peanut is a major crop of Gujarat especially of saurashtra region (India). Peanut oil contains highly unsaturated mono acids such as linoleic acid and oleic acid which can be used for the synthesis of polyether ester urethanes. These monoacids have been allowed to react with glycerol in presence of weak acid (Acetic acid) and strong acid (Sulfuric acid) as catalyst to prepare polyether ester polyols (PEEP) which were further reacted with isophorone diisocyanate to synthesize polyether ester urethane (PEEU). Physico-chemical properties of polyether ester polyol were determined by measuring acid value and intrinsic viscosity of polymers. For determination of molecular weight and structure GPC, FTIR and NMR spectroscopy were used. Polyether ester urethanes have been used for coating and casting purposes. Thermal stability of cured product has been determined using thermogravimetric analysis. Mechanical properties of coating like pencil hardness, scratch hardness, adhesion and flexibility have been found out. Being biodegradable in nature, soil degradation test of polyether ester urethanes have been performed. After continuous exposure to moist soil, results show polyether ester urethanes started to degrade after 120 days.