Ultem® , thermoplastic

Polyether Imides. Polyether imides (PEIs) are amorphous, high performance thermoplastic polymers that have been in use since 1982. The first commercial polyether imides were the Ultem series developed by the General Electric Co. The first, Ultem 1000 [61128-24-3] is prepared from phthahc anhydride, bisphenol A, and meta-phenylenediamine and has the following stmcture ... 

Thermoplastic Condensation Polyimides. These include General Electric s Ultem Resin and Amoco s Todon polyamideimide although the latter is no longer offered as injection moldable pellets, but as compression moldable powder and in solution. Another resin, P-84, originally developed by Upjohn but now made by Lenzing (Austria), is based on benzoquinone dianhydride and aromatic isocyanates. 

Figure 32.1. Polar diagrams for three thermoplastic materials, CYCOLOY (a PC/ABS blend), ULTEM (polyetherimide) and NORYL (a styrenic PPO). The shaded area indicates the range...

Diglycidyl ether of bisphenol-A (DGEBA), epoxy resin (YD 128, Kuk Do Chem., Mn = 378), and bisphenol-A dicyanate (BPACY, Arocy B-10, Ciba-Geigy) were used as the thermoset resin. 4,4 -diaminodiphenyl sulfone (DDS, Aldrich Chem. Co.) was used as a curing agent for epoxy. Polyetherimide (PEI, Ultem 1000, General Electric Co., M = 18,000) and 2-methyl imidazole (2MZ, Aldrich Chem. Co.) were used as the thermoplastic modifier and catalyst. 

Not all polyetherimides are limited by their tractability, however. Certain aromatic polyetherimides are characterized by a combination of properties that makes them potential engineering thermoplastics (90). One of these polymers contains an isopropylidene unit in the backbone to enhance the solubility. It is a mol ding material introduced by General Electric in 1981 and sold as Ultem resin. Attractive features include high temperature stability, flame resistance without added halogen or phosphoms, high strength, solvent resistance, hydrolytic stability, and injection moldability. 

As to the polymers, the most important of them - considering production figures - are very probably the poly(ether-imide)s (PEIs), marketed under the trade name Ultem. Neat PEI resins are amorphous, soluble polymers that show Tg values around 220 °C. They can be processed from the melt by conventional means, and offer a price-performance balance that enables them to compete successfully in the market of engineering thermoplastics. 

A mixture of a BMI (Compimide 796) with 4,4 -bis(orf/zo-propenylphe-noxy)benzophenone (TM 23) was blended in solution with Udel 700 (polysul-fone from Union Carbide), Ultem 100 (General Electric polyether imide), and PH 10 (Bayer polyhydantoin) (Fig. 35). The thermoplastics were introduced at various concentrations up to 33%. A phase segregation did not appear with PH 10, but two phases were observed with Ultem. With both semi-IPNs the observed Glc were found to be four- to fivefold the Glc of the neat BMI [113]. 

Substrates used included fiber-reinforced epoxy base polymer [FRP], nylon 66, polytetrafluoroethylene [Teflon], poly(ethylene terephthalate) [PET], phenolic resin, and thermoplastic polyimide [ULTEM, GE]. FRPs were the primary substrates used. Initially, they were cleaned with detergent in an ultrasonic bath followed by rinsing with deionized water and alcohol. For further cleaning, they were treated with oxygen plasma (1.33 seem, 60 W, 5 min) followed by a hydrogen plasma treatment (3 seem, 60 W, 5 min). 

Thermoplastic polyetherimide Ultem can be formulated with high temperature foaming agents such as 5-phenyldihydro-l,3,4-oxadiazinone to produce structural form products [99] by injection molding. PEI could be readily imbibed with various volatile organic compounds such as chlorinated hydrocarbons [100] and acetone [101]. 

Several liquid cryatalline polymers were melt blended with an amorphous (Ultem) and two semicrystalline (PEEK and PPS) engineering thermoplastics in a single screw extruder. Flat film was processed with different degrees of stretch imparted while the film was being cooled. In the case of Vectra, which was thought to be ideally suited to be blended with PPS based on thermal and rheological... 

An alternative route to the formation of poly(imide)s is the nitro-displace-ment reaction to form the Ultem series of polymers, first exploited by White et al. [11] at General Electric. These, and similar materials, have application in composite materials and as specialty thermoplastics. Compared to the amic acid route described above, the nitro-displacement reaction is highly controlled, and materials of high chemical regularity produced, as demonstrated by White et al. [11] in their solution-state NMR study of Ultem poly(imide)s. 

The newest engineering thermoplastic is a polyetherimide that was formally announced by General Electric Company in 1982 (16). This amorphous polymer is designated Ultem resin and resulted from the research work of a team headed by J. G. Wirth in the early 1970s (9). The early laboratory process involved a costly and difficult synthesis. Further development resulted in a number of breakthroughs that led to a simplified, cost-effective production process. The final step of the process involves the imidization of a diacid anhydride with m-phenylene diamine (Figure 13). 

Polyetherimide (Ultem 1000, GEC) is a high performance engineering thermoplastic with high heat distortion temperature (> 200°C), high mechanical strength and inherent flame-retardancy characteristics. Recently blends of polyetherimide with polycarbonate have been commercially offered as thermoformable sheets and as molding compounds (Table 15.28). The primary reason for... 

Commercial polyetherimide (PEI Ultem , GEC) is an amorphous, high performance thermoplastic with its repeat unit structure containing both the rigid aromatic imide units and the somewhat more flexible aromatic ether units. 

Poly(aryl ketones) (PEEK, PEK, and PEKK) are commercial high temperature polymers offering an excellent combination of properties combined with thermoplastic behavior. Poly(aryl ether ketone) PAEK blends have been reviewed by Harris and Robeson [1989]. Miscibility with PEI (Ultem 1000 GE) and other PI containing isopropylidene bridging units was noted. Arzak et al. [1997] reviewed the performance ofPEEK/PEI blends and noted a synergistic behavior in ductility and impact strength as reported earlier. Utility of these blends as a thermoplastic matrix candidate for advanced composites has been proposed [Harris and Robeson, 1989 Davis et al., 1992]. 

In the electronics industry, one of the most successfiil uses of advanced composites has been in PCBs. General Electric s Ultem polyetherimide is used in transport PCBs, especially aerospace an missile guidance systems. Polysufibnes and other high-performance thermoplastics are being used in multilayer PCBs for mainframes and supercomputers operating at gigahertz frequencies. 

Ultem (Series) Poly(imide), thermoplastic General Electric... 

PI is widely used as a protective material or an insulation material in the electronic field due to its good properties, e.g., high mechanical strength, high thermal resistance, and solvent resistance. Selected physical properties of a thermoplastic PEI are shown in Table 15.5. Ultem is obtained from bisphenol A dianhydride and MPD. It has a glass transition temperature of 217°C. It should be emphasized that there are a lot of different PI resins with deviating properties. Thus the data given in Table 15.5 are not plainly representative for Pis. 

Both polysulfone and the polyetherimide are thermojdaslics whieh withstand higher temperatures than epoxies such as DGEBA. The effect of (43) a polysulfone (Udel, 43a) and polyetherimide (Ultem, 43b) thermoplastics on the properties of a tetra-2,3-epoxypropylamine, N,N,N, N -tetra-2,3-epoxypropyl-, -bis(4-aminophenyl)-p-diiso-propenylbenzene (HPT Resin 1071,43c) has been studied and also the effect of these thermoplastics on the resin di-2,3-epoxypropyl-9,9-bis (hydro phenyl)fluorene (HPT Resin 1079,43d). Both these resins have a stiff backbone and were developed for use as amatrix resin for advanced composites. They can be cured with the aromatic dianune, -bis(3,5-dimethyl-4-aminophenyl)-p-diisopropylbenzene (43e). These resin curing agent combinations exhibit greatly improved hot/wet performaiKe over that of traditional epoxies. 

Figure 23.47 A selection of carbon fiber thermoplastic components, (a) Carbon fiber reinforced APC thermoplastic aircraft floorpanel (EH101 Merlin) Makes use of improved toughness and damage tolerance of thermoplastic materials, (b) Bulkhead or wing stiffener made from carbon fiber/PEEK thermoplastic Made in one piece apart from the ring stiffener, (c) Underslung carbon fiber APC2 reinforced thermoplastic tailplane. This item was made over 10 years ago and was the largest piece of flying thermoplastic in the world Fins are fabricated from Ultem 1000 (PEI). Source Courtesy of GKN.

Polyetherimides (PEI) are a newer class of amorphous thermoplastics with high-temperature resistance, impact strength, creep resistance, and rigidity. They are transparent with an amber color. The polymer is sold under the trade name of Ultem (General Electric) and has the stracture shown in Eig. 2.20. It is prepared from the condensation polymerization of diamines and dianhydrides. ... 

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