Polyamide-imide plastic

Table 2.14 Properties of Typical Polyamide-Imide Plastics (1) ...

TrimeUitic anhydride is converted to PVC plasticizers, polyesters, water-soluble alkyd coatings, and polyamide—imide resias. The trimellitate plasticizers have a lower volatility than those derived from phthaUc anhydride (see Plasticizers). 

Fig. 6-14 specific modulus = modulus/density. Plastics include use of the heat-resistant TPs such as the polimides, polyamide-imide, and others. Table 6-21 provides data on the thermal properties of RPs. To date at least 80 wt % are glass fiber and about 60 wt% of those are polyester (TS) type RPs. 

Polyamide-imides are handicapped by the cost (justified by the performances), a high density, the small numbers of grades and sources. PAI can slowly absorb some water in a wet environment, which has a plasticizing effect and can lead to a significant linear expansion. 

Polyamide-imide is an engineering plastic used only for specialized and technical applications. 

A comparison of the abrasive wear by Bohm (1990) found that the hard and more brittle plastics, such as polyacetals, polyamide-imide, and polycarbonates, are less abrasion resistant than softer and tougher materials such as the polyethylenes and polyurethanes. Table 7.2 details some comparative... 

ZONE 7 polyamide-imide, polyimide ZONE 8 plastics now being developed us ... 

Figure 2. The dipole moment of the absorbed water molecules varies from approximately 1.8 to 0.9 for the polyimides and from 1.1 to 0.7 for the polyamide-imides corresponding to fractional polarizabilities of l.O/i -0.4/x. The low values of p (<0.5p ) as seen in all the amide-imide po ymers and several of the ° polyimides, indicate restricted mobility of the water molecules. In the amide-imide polymers, we believe this is due to increased water-polymer interactions such as hydrogen bonding. Other evidence of hydrogen bonding in polyamide-imides is the water-induced plasticization and Tg lowering frequently observed.

Pseudocumene is an item of commerce, and comprises approximately 15% of the heavy gasoline fraction. Its major use is for oxidation to trimellitic acid or its anhydride. These compounds have a number of uses, but the major ones are to form temperature resistant plasticizers for pvc (e.g. as the trioctyl ester), to form high performance plastics (e.g. the polyamide-imides),... 

The Kinel materials produced by Rhone-Poulenc are polybismaleinimides of the type shown in Figure 4.22. These materials have chain-end double bonds, as explained previously, can be processed like conventional thermosetting plastics. The properties of the cured polymers are broadly similar to the polyimides and polyamide-imides. Molding temperatures are usually from 200°C to 260°C. Post-curing at 250°C for about 8 h is necessary to obtain the optimum mechanical properties. 

The Ford Polimotor, which has a virtually all-plastic engine that offers a weight saving of some 60% compared with conventional components, uses polyamide-imide for moving parts with fuel saving advantages. 

Polyamide-imide resin plastics, reinforced Dipropylene glycol Polypropylene plastics, surface-coating Bismuth subsalicylate plastics, vinyl Ammonium acetate plastisols... 

Johson, S.H., Polyamide-imide, in Modem Plastics Encyclopedia Handbook, McGraw-Hill, New York, 1994, p. 14. 

They are easily bonded with epoxy or urethane adhesives however, the temperature resistance of the adhesives do not match the temperature resistance of the plastic part. No special surface treatment is required other than abrasion and solvent cleaning. Polyetherimide (ULTEM ), polyamide-imide (TORLON ), and polyethersulfone can be solvent cemented, and ultrasonic welding is possible. 

This is an engineering plastic designed for thermal/electrical applications requiring high dimensional stability. This material exhibits superior electrical and mechanical performance at continuous use temperatures ranging from -60 to 260 °C. Pyropel HDT polyamide-imide (PAI) produced by Albany International [35] has enhanced properties without the need for post-curing. 

Polyamide-imides, due to their high relative cost compared to common engineering plastics such as nylon and polycarbonate, are used when the application conditions require the property benefits of these materials and where lesser polymeric materials would fail. In addition to this, they... 

The endurance benefits and performance characteristics of polyamide-imides qualify them to be an excellent replacement for metal in aerospace components. Inherent nonflammability, chemical resistance, and superb strength at elevated temperatures allow polyamide-imide compounds to be used in metal applications once unheard of for plastic materials. Neat resin, friction and wear, along with glass- and carbon-reinforced polyamide-imide compounds are incorporated in a variety of parts and locations in aerospace vehicles. 

Due to the specialty nature and niche applications for polyamide-imide parts, many of these low-volume pieces are machined from preformed stock shapes. Toray, based in Japan, is producer of polyamide-imide resin that it converts to polyamide-imide parts and stock shapes, largely for the Asian markets. In the United States, Quadrant EPP supplies extruded Torlon polyamide-imide rod and plate stock as well as compression-molded ingots and shapes. Drake Plastics extrudes custom profiles in addition to standard shapes from Torlon resins. Injection-molded Torlon polyamide-imide stock shapes are available through Parkway Products. 

The Swiss company, WW Fischer, offers PTFE (Teflon PTFE or Hostaflon), PBT (Celanex, Crastin, Ultradur or Valox) or PEEK (Victrex) insulator material options in its 405 series of cylindrical connectors according to the requirements of working temperature and other criteria. PEEK is an expensive polymer which tends to be employed when other materials fail to meet the specification requirements of the application. Other Fischer connector types use polyamide-imide (Torlon) or POM (Celcon, Delrin or Hostaform). Elastomeric seals used by Fischer in conjunction with their connectors are made from acrylonitrile-butadiene rubber (NBR N BUNA) or to MIL-P-25732, fluoroelastomer (FPM VITON), polychloroprene elastomer (CR Neoprene), ethylene-propylene diene elastomer (EPDM) and styrene-ethylene-butadiene-styrene thermoplastic elastomer (TPE-S or TPE-O) where each compound is followed by its trade name. Fischer s Swiss competitor, Lemo, manufactures a similar range of connectors including the Redel types which have a plastic body. 

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