Ultem resins

ULTEM 1000 resin Ultem resins UltMat Ultimate... 

A PEL/polycarbonate blend with higher impact resistance Ultem 1000 resins melt filtered to 40 microns... 

Many different lesins can be made by varying R and R, as in Ultem resins. 

Ultem PEI resins are amber and amorphous, with heat-distortion temperatures similar to polyethersulfone resins. Ultem resins exhibit high modulus and ate stiff yet ductile. Light transmission is low. In spite of the high use temperature, they are processible by injection mol ding, stmctural foam mol ding, or extmsion techniques at moderate pressures between 340 and 425°C. They are inherently flame retardant and generate Httie smoke dimensional stabiUties are excellent. Large flat parts such as circuit boards or hard disks for computers can be injection-molded to maintain critical dimensions. 

PEI polymers exhibit minimal creep underload. Eor example, unreinforced Ultem 1000 maintains part dimensions over thousands of hours at room temperature at a loading of 34 N/mm (4930 psi). PEI resins are available with HDTs ranging to 220°C (Ultem 5000). PEI copolymers with siUcone mbber allow for flame-retardant, high temperature appHcations such as plenum wire coatings (Siltem). Reinforcement of PEI resins improves their temperature performance. Table 13 compares unreinforced and 20% glass-reinforced Ultem resins. 

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. 

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. 

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). 

GE Plastics, ULTEM Resin Design Guide, http //tools.geplastics.com, 2006. 

Methylene chloride, with or without a 1-5% solution of Ultem resin, is recommended hy General Electric, the manufacturer. Moderate pressures of 6.89-41.3 MPa for 5 minutes are required. ... 

ADVANTAGES AND DISADVANTAGES OF THE BLEND Higher impact resistance and slightly lower heat resistance than standard PEI Ultem resins. Typical properties of Ultem resins such as stain and chemical resistance, long term hydrolytic stability are retained. These materials provide better stain resistance and surface hardness than polysulfone blends. The 300 series has high heat resistance combined with flame retardant properties. 

Polyetherimides are a new family of condensation polymers. The key reaction step in each of their synthetic sequences is an aromatic nitro-displacement reaction which produces the diaryl ether linkages in high yield. Physical properties can be varied over a wide range depending on the choices of bis-phenol, diamine, and positional isomer incorporated into the backbone of the polymer. Our study of these materials has led to the commercial introduction of ULTEM Resin as the first in a series of new high performance engineering thermoplastics. 

These are very demanding end uses with tough standards including lire resistance. National Nonwovens recently launched their Ultra-ProTechtor lire blocker range for aircraft seating applications. These fabrics use fibres made from SABlC s flame-retardant ULTEM resin, a polyetherimide material [14]. 

Ultem resin blends are designed to fill the gap between polycarbonate and polyetherimide resins. Key features are good flow, intermediate heat performance and price. Blends include Ultem 1285, Ultem ATX, a polycarbonate-ester blend, and Ultem HTX. 

PEI resins reinforced with up to 40 wt % fiber glass are available. The American Cyanamid Co. uses an Ultem-type resin with carbon fibers to form their Cypac 1000 series prepregs (31). The moisture content of the resin must be less than 0.05% prior to melt processing to minimise thermal degradation. 

The Ultem PEI resins compete with PAI, polyarylethersulfone, nylon, and polyester resins in certain markets. General Electric Co. is the sole U.S. manufacturer of PEI resins. High cost coupled with stiff competition from metals and ceramics have limited growth. 

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. 

In addition, ASA may be blended with other polymers that themselves exhibit high heat distortion temperatures. For example, blends of poly(ether imide) and ASA exhibit an improved heat distortion temperature, improved flexural properties and tensile properties in comparison to the ASA component alone and have lower impact strengths as well (35). The statement above has been exemplified using Ultem 1000 as a poly(ether imide) resin and Geloy 1020 as ASA component. 

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. 

Samples of unfilled resins (ULTEM 1000) were utilized to examine the changes occurring to the plastic during the chemical treatments. Adhesion data was generated using the glass-filled resin (ULTEM 2312). 

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). 

Figure 21.6 SEM micrographs of (a) as-received Teflon, (b) Nylon 66, (c) Phenolic Resin, and (d) ULTEM surfaces (xlOOO).

---