Polyetherimide Ultem Research Articles

New superstructural thermoplastics and carbon composite materials based on them

New superconstructional polyarylates with glass transition temperatures from 216 to 280°C and polyethersulfones with glass transition temperatures from 230 to 255°C have been developed. On the basis of these polymers, industrial polysulfone PSFF-30, PSF-150, polyethersulfone E-3010, polyetherimide Ultem 1000, PEEK and PEKK, and two types of carbon fabrics, thermoplastic prepregs and consolidated carbon composite plates were obtained, and their mechanical properties under compression and three-point bending were determined.

Synthesis of Aromatic Polyimides Based on 3,4'-Oxydianiline by One-Pot Polycondensation in Molten Benzoic Acid and Their Application as Membrane Materials for Pervaporation.

A series of aromatic polyimides based on the asymmetrical diamine 3,4ʹ-oxydianiline and various tetracarboxylic acid dianhydrides, both “rigid” and “flexible” structure, have been synthesized using the original method of one-pot high-temperature catalytic polycondensation in molten benzoic acid. The synthesized polyimides were investigated using fourier-transform infrared (FTIR) and 1H NMR spectroscopy, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), thermomechanical analysis (TMA) and wide-angle X-ray scattering (WAXS). It was found that the synthesized polyimides, depending on the used dianhydride, are characterized by different solubility in organic solvent and molten benzoic acid, molecular weight, glass transition temperature (Tg) from 198 to 270 °C, an amorphous or semi crystalline structure with the degree of crystallinity from 41 to 52%. The influence of the method of synthesis on the formation of the crystalline phase of polyimides was studied, and the obtained results were compared with the literature data. The effect of dianhydride chemical structure on the performance of polyimide in pervaporation more specifically, dehydratation of azeotropic isopropanol solution was investigated and compared with the commercially available polyetherimide Ultem 1000™. Membrane structure was studied using scanning electron microscopy. It was found that polyimide PI-DA is the most effective for separation of 88 wt.% isopropanol/12 wt.% water mixture compared to the polyimide PI-6FDA and commercial polyetherimide Ultem 1000™ demonstrating normalized permeation flux of 2.77 kg µm m−2 h−1 and separation factor of 264 (water content in permeate 97 wt.%).

Stability of Charge Distributions in Electret Films on the nm-Scale.

Electret materials find use in various applications, such as microphones or filter media. In recent years, electrets have been used also increasingly on the micrometer scale, for example, in MEMS or for nano-xerography. However, for these applications, it becomes more important to prepare defined charge structures with sub-micrometer features. On the macroscopic level, the technique of isothermal potential decay at elevated temperatures has been developed to study aging effects and charge retention capabilities in electret materials. Here, we extend this technique to the nm-level by means of AFM-based methods, such as contact charging by AFM and the Kelvin probe force microscopy. Defined charge distributions in polyetherimide (PEI) ULTEM 1000 thin-film electrets have been studied for the first time with a high lateral resolution on the nanometer scale. We found a linear correlation between externally applied contact charging potential on the AFM-tip and the resulting relative surface potential on the PEI film. Charge decay at elevated temperatures is independent from the length scale. The same time dependence as for macroscopic, homogenously charged films could be established. We observe a potential decay only at an elevated temperature of 120 °C and no significant lateral charge transport. Thus, we propose a thermally enhanced charge carrier release from surface traps and a subsequent charge migration to the back electrode as the dominant mechanism. This finding is in-line with the observation that potential decay can be reduced also on the nm-level by pre-annealing the film slightly below the glass transition temperature. In contrast to many polymeric or inorganic electrets, no lateral charge migration is observed. Therefore, the charge patterns are preserved for PEI ULTEM 1000 thin-film electrets, which makes it a good candidate as electret for applications in MEMS or similar applications.

A Comparative Study of Turbulence Methods Applied to the Design of a 3D-Printed Scaffold and the Selection of the Appropriate Numerical Scheme to Simulate the Scaffold for Tissue Engineering

Current commercial software tools implement turbulence models on computational fluid dynamics (CFD) techniques and combine them with fluid-structural interaction (FSI) techniques. There are currently a great variety of turbulence methods that are worth investigating through a comparative study in order to delineate their behavior on scaffolds used in tissue engineering and bone regeneration. Additive manufacturing (AM) offers the opportunity to obtain three-dimensional printed scaffolds (3D scaffolds) that are designed respecting morphologies and that are typically used for the fused deposition model (FDM). These are typically made using biocompatible and biodegradable materials, such as polyetherimide (PEI), ULTEM 1010 biocompatible and polylactic acid (PLA). Starting from our own geometric model, simulations were carried out applying a series of turbulence models which have been proposed due to a variety of properties, such as permeability, speed regime, pressures, depressions and stiffness, that in turn are subject to boundary conditions based on a blood torrent. The obtained results revealed that the detached eddy simulation (DES) model shows better performance for the use of 3D scaffolds in its normal operating regime. Finally, although the results do not present relevant differences between the two materials used in the comparison, the prototypes simulated in PEI ULTEM 1010 do not allow their manufacture in FDM for the required pore size. The printed 3D scaffolds of PLA reveal an elastic behavior and a rigidity that are similar to other prototypes of ceramic composition. Prototypes made of PLA reveal unpredictable variability in pore and layer size which are very similar to cell growth itself and difficult to keep constant.

Mass spectrometric analyses of high performance polymers to assess their radiopurity as ultra low background materials for rare event physics detectors

The mass concentrations of 232Th and 238U in several strong, unfilled, high performance polymers are reported as measures of their radiopurity. Highly radiopure polymers are required as dielectric materials in the construction of rare event physics detectors, in order to minimize background signals arising from the detector materials themselves. New data are reported for carefully sourced samples of polyetheretherketone (PEEK), polyetherketoneketone (PEKK), a polyamide imide (PAI, branded as Torlon) and polybenzimidazole (PBI). Data for solid polyetherimide (PEI) are also discussed and new data for PEI in the form of a commercial 3D printing filament stock are reported. Strong high performance polymers PEKK, PBI, PAI and PEI were found with levels for 232Th and 238U that are below one mBq/kg, including the PEI 3D printing filament. Specifically, for 232Th and 238U respectively, in μBq/kg (emphasis “micro”Bq/kg), we found values of 149 and 184 for Arkema Kepstan PEKK 6002 flake; 69 and 2250 for Solvay Ketaspire PEEK flake; 346 and 291 for PBI Performance Products low metals grade 100 mesh PBI powder; 66 and 105 for Drake Plastics PAI Torlon T-4200 pellets; 401 and 285 for Drake Plastics cured PAI rod; 32 and 41 for Ensinger PEI Ultem 1000 solid; and 15 and 85 μBq/kg, for ThermaX PEI Ultem 1010 filament material. These results were all obtained using a novel dry ashing method in crucibles constructed of ultra low background (ULB) electroformed copper. Samples were spiked with 229Th and 233U as internal standards prior to ashing and determinations were made by inductively coupled plasma mass spectrometry (ICP-MS). Radiopurity is displayed graphically relative to numerical measures of mechanical strength for these and several other polymers.

The Effect of Conformation Order on Gas Separation Properties of Polyetherimide Ultem Films.

Changes of the spectral characteristics of absorption bands depending on the films’ treatment method were registered for polyetherimide Ultem films. The possibility of selection of structural criteria (the ratio of the functional groups absorption bands intensities) showing all conformational changes in elementary unit with metrological processing of the results is shown. It is demonstrated that film formation from chloroform solution leads to elementary unit fragments, Ph–O–Ph′, which have an effect on macromolecule conformation and result in increasing of space between fragments of macromolecules (local polymer matrix packing loosening). Desorption of residual chloroform from films by ethanol or supercritical CO2 leads to a change of conformers set in Im–Ph–Im′ units. Quantum chemical modeling showed the possibility of convergence of these fragments in neighboring macromolecules, and consequently of interchain π–π interaction (local densification of chain packing of the polymer matrix). After annealing at a temperature higher than glass transition temperature, the polyetherimide film exhibits the most disordered (amorphous) state at all of the fragments. It is demonstrated that the results, obtained by the combination of theoretical and experimental vibrational spectroscopy methods, are in good agreement with data of chain packing ordering found by analysis of gas separation parameters.

Feasibility of single-use 3D-printed instruments for total knee arthroplasty.

This aim of this study was to assess the feasibility of designing and introducing generic 3D-printed instrumentation for routine use in total knee arthroplasty. Instruments were designed to take advantage of 3D-printing technology, particularly ensuring that all parts were pre-assembled, to theoretically reduce the time and skill required during surgery. Concerning functionality, ranges of resection angle and distance were restricted within a safe zone, while accommodating either mechanical or anatomical alignment goals. To identify the most suitable biocompatible materials, typical instrument shapes and mating parts, such as dovetails and screws, were designed and produced. Before and after steam sterilization, dimensional analysis showed that acrylonitrile butadiene styrene could not withstand the temperatures without dimensional changes. Oscillating saw tests with slotted cutting blocks produced debris, fractures, or further dimensional changes in the shape of Nylon-12 and polymethylmethacrylate (MED610), but polyetherimide ULTEM 1010 was least affected. The study showed that 3D-printed instrumentation was technically feasible and had some advantages. However, other factors, such as whether all procedural steps can be accomplished with a set of 3D-printed instruments, the logistics of delivery, and the economic aspects, require further study. Cite this article: Bone Joint J 2019;101-B(7 Supple C):115-120.

Influence of Chemical Structure on Gas Separation Properties of Polymer Materials Based on Polyetherimide Ultem® and Silicon-Containing Copolyetherimide Siltem®

Influence of Chemical Structure on Gas Separation Properties of Polymer Materials Based on Polyetherimide Ultem® and Silicon-Containing Copolyetherimide Siltem®

Influence of swelling in supercritical carbon dioxide of Ultem and polyhexafluoropropylene thin films on their gas separation properties: comparative analysis

Thin films of polyetherimide Ultem and polyhexafluoropropylene serially underwent different treatments: drying to a constant weight, annealing at temperature slightly higher than glass transition temperature, and swelling in supercritical carbon dioxide and their gas transport properties were investigated.

Dehydration of industrial isopropanol (IPA) waste by pervaporation and vapor permeation membranes

ABSTRACTWe have investigated the feasibility of using polymeric membranes for the dehydration of industrial isopropanol (IPA) waste from MSD International GmbH by pervaporation and vapor permeation in this study. Four types of membranes were employed. They were (1) thin‐film composite hollow fiber consisting of a polyamide selective layer and a polyetherimide Ultem® substrate, (2) dual‐layer hollow fiber comprising an outer cellulose triacetate (CTA) layer and an inner Ultem® substrate, and (3) two commercially available Sulzer flat‐sheet membranes. The dual‐layer hollow fiber shows the most balanced separation performance in terms of flux and separation factor for the dehydration of industrial IPA waste because it has a porous substructure and a thin dense selective layer. Under vapor permeation tests at 125 °C, it has a flux of 13.41 kg/m2 h and a separation factor of 1332. This study demonstrates the great potential of using polymeric membranes to dehydrate industrial IPA waste for pharmaceutical and electronic industries. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45086.

Improvement of processing and mechanical properties of polyetherimide by antiplasticization with resorcinol bis(diphenyl phosphate)

ABSTRACTThis article describes the antiplasticization of a commercial polyetherimide ULTEM® series 1000 [poly(bisphenol A‐co‐4‐nitrophthalic anhydride‐co‐1,3‐phenylenediamine) by resorcinol bis(diphenyl phosphate)] (RDP) and its implications on the thermomechanical processing, namely extrusion and injection molding, as well as on the thermal and mechanical properties of the formulations. This antiplasticization effect allows the processing of polyetherimide formulations at lower temperatures in comparison with neat polymer due to the progressive decrease of the glass transition temperature with increased RDP concentration, as observed by differential scanning calorimetry and dynamic mechanical analysis. The decrease of Tg occurs concomitantly with the overlap of the glass transition and β relaxation and with the shift of the γ relaxation to higher temperatures. These changes in the relaxation spectrum of polyetherimide formulations are possibly responsible for the increase of the tensile strength and Young's modulus and changes in the fracture mechanism, as observed by stress–strain tests and by scanning electron microscopy, respectively. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40619.

Synthesis and Characterization of Polyetherimides with 3‐Methoxy‐1,2‐propanediol Moieties

AbstractPolyetherimides have been evaluated as non‐toxic and steam‐sterilizable and are therefore potentially suited for biomedical applications. To enable a broader range of potential applications, polyetherimides with lower Tg, higher elasticity at room temperature and better processability are required. Our concept was to explore, whether the incorporation of 3‐methoxy‐1,2‐propanediol moieties in the main chain lead to a reduction of Tg and increase the elastic properties of the polymer compared to commercially available polyetherimides from 4,4′‐(4,4′‐isopropylidenediphenoxy)bis(phthalic anhydride) and 1,3‐diaminobenzene. Two different monomers were synthesized and co‐condensated with each other or using 4,4,4′‐(4,4′‐isopropylidenediphenoxy)bis(phthalic anhydride), respectively. The results proofed the successful synthesis and polymerization leading to polymers with molecular weights up to Mn = 6,400 g/mol. The polymers showed lowered Tg, resistance to heat up to 400 °C, tendencies to reduced contact angles and partially reduced E‐moduli in comparison to the commercial polyetherimide ULTEM 1000.

Charge storage performance of polyetherimide Ultem®1000—Influence of secondary antioxidants and purification

AbstractThe performance of a polymeric electret material depends on many parameters, and besides chemical structure, charging conditions, and application temperature, other factors, such as grade, manufacturer, processing history, and additive package, are critical. Commercial polyetherimide (PEI) Ultem®1000 films exhibited satisfying electret properties as revealed by an isothermal potential decay (ITPD) to 75% of the initial surface charge after 24 h at 90°C. It was found that after purification by reprecipitation this value drops to 34% and that the same PEI synthesized by two different methods revealed to be a very poor electret with charge retention of almost zero. Assuming that an additive in the commercial material might be responsible for this behavior, we identified an organophosphonite which is commonly used as antioxidant in high‐temperature polymers. We incorporated this additive by melt compounding into purified PEI and found a dramatic increase in charge retention to 79% of the initial charge at an additive load level of 0.5 wt %. By immersing Ultem®1000 films in water, the electret behavior was further improved and almost 100% charge retention was achieved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

In situ compatibilization of a polyetherimide and a thermotropic polyester using an epoxy resin

Abstract This study examines the compatibilization of the polyetherimide Ultem 1000 with the thermotropic liquid crystalline polymer Vectra A 950 by using an epoxy resin (PKFE) as compatibilizer. IR spectroscopy and electron-microscopic morphological analysis indicate the grafting of PKFE molecules on fibrillar domains of Vectra during melt mixing. Moreover, morphological analysis shows that the addition of PKFE improves the dispersion and decreases the size of Vectra fibrils. Both Vectra and PKFE significantly reduce the glass transition temperature of Ultem in ternary blends. The tensile modulus and the ultimate strength of the blends are improved with respect to those of neat Ultem. However, the final materials are very fragile. The roles of Vectra and PKFE are discussed.

Photo-oxidation products of polyetherimide ULTEM determined by MALDI-TOF-MS. Kinetics and mechanisms

Poly 2,2-bis4-(3,4-dicarboxyphenoxy) phenylpropane dianhydride-1,3-phenylendiamine copolymer (ULTEM) was subjected to photo aging in the attempt to find evidence on the structure of the species formed in the oxidative degradation. The oxidation was followed as a function of the exposure time by MALDI and SEC/MALDI techniques. The SEC curves showed extensive degradation, with the formation of low molar mass oligomers having different end groups. Valuable structural information on the photo-oxidized ULTEM species was extracted from the MALDI spectra of the photo-oxidized ULTEM. These showed the presence of polymer chains containing acetophenone, phenyl acetic acid, phenols, benzoic acid, phthalic anhydride and phthalic acid end groups. The mechanisms accounting for the formation of photo-oxidation products involve several simultaneous reactions: (1) photo-cleavage of methyl groups of the N-methyl phthalimide terminal units; (2) photoxidative degradation of the isopropylidene bridge of BPA units; (3) photo-oxidation of phthalimide units to phthalic anhydride end groups: (4) hydrolysis of phthalic anhydride end groups. The kinetic behaviour of all the species detected is in agreement with the predictions of the reaction mechanisms hypothesized.

Synthesis and Properties of Designed Low-k Fluoro-Copolyetherimides. Part 1

Polyetherimides are versatile melt-processable engineering resins. A series of fluoro-polyetherimides compositions based on diether-containing diamines were designed on paper and their dielectric constants (ϵ′) estimated before their synthesis. Experimentally determined ϵ′ values were compared with the estimated values. The amorphous polyetherimides containing bis-trifluoromethyl groups exhibited not only low dielectric constants—lower than those of the commercially available polyetherimide ULTEM 1000 and polyimide Kapton H at 1 kHz—but also excellent long-term thermo-oxidative stability and reduced water absorption relative to non-fluorinated polyimides.

Synthesis and properties of fluoro‐polyetherimides

AbstractA series of amorphous fluoro‐polyetherimides based on 2,2′‐bis(3,4‐dicarboxyphenyl) hexafluropropane dianhydride (6FDA) and di‐ether‐containing diamines 4,4′‐bis(3‐aminophenoxy)diphenyl sulfone (m‐SED), 4,4′‐bis(4‐aminophenoxy)diphenyl sulfone (p‐SED), 4,4′‐bis(4‐aminophenoxy)diphenyl propane (BPADE) were synthesized. These melt processable polyetherimide polymers fromp‐SED and BPADE showed excellent electrical properties. The dielectric constants, 2.74 and 2.65 at 10 MHz respectively, are lower than commercially available polyetherimide ULTEM® 1000, and polyimide Kapton® H films. In addition, we found that trifluoromethyl groups‐containing polyimides not only show extraordinary electrical properties, but they also exhibit excellent long‐term thermo‐oxidative stability and reduced water absorption relative to non‐fluorinated polyimides. The weight retention of these fluoro‐polyetherimides at 315°C for 300 h in air varies from 93% to 98%. Whereas, their moisture absorption at 100 RH at 50°C was in the range of 0.3% to 1.05%, which is much lower than those of Ultem 1000 and Kapton H. In the case of fluoro‐polyetherimides fromp‐SED andm‐SED (paraandmetaisomers) diamines with ‘ether’ and sulfonyl (‐SO2‐) spacer groups, thed‐spacing andTgvalues decreased from 4.72Å to 4.56Å and 293°C to 244°C respectively. Similarly, the transparency of these polymer films (in the range of 80% to 90%) at 500 nm solar wavelength was higher than Ultem 1000 and Kapton H.

Transport of CO2, H2, N2 and mixtures thereof through polyetherimide Ultem 1000 membranes

Transport of CO2, H2, N2 and mixtures thereof through polyetherimide Ultem 1000 membranes

Physical ageing studies in polyetherimide ULTEM 1000

Thermally stimulated depolarization currents (TSDC) and differential scanning calorimetry (DSC) have been used to study the effect of physical ageing in polyetherimide (PEI: ULTEM 1000®). Ageing temperatures (T a ) between 48 and 8°C below the glass transition temperature (T g ) measured by DSC at 10°C min -1 heating rate (T g =218°C), and ageing times (t a ) between 0 and 8640min, were analysed. Calorimetric results show the presence of an endothermic peak, associated with the enthalpy recovery at the glass transition. This peak shifts towards higher temperatures and its height and area increase as the annealing time increases for a given T,. The maximum enthalpy relaxation is achieved at T a = T g - 18°C (T a = 200°C) for every annealing time, indicating that this is the optimum temperature to age this material. TSDC results show for each T a a shift of the α peak towards higher temperatures, and a considerable decrease in maximum current and area as t a increases. The activation energies (E a ), calculated from the TSDC curves for the α relaxation, are mainly independent of the annealing temperature and time. The pre-exponential factor for the relaxation time (τ 0 ), evaluated from the same curves, shows a slight decrease when the annealing time is increased at a given temperature.

Physical ageing studies in polyetherimide ULTEM 1000

Physical ageing studies in polyetherimide ULTEM 1000