High-Performance Thermoplastics

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 ... 

In most applications, polyester and vinyl ester resins are used as the matrix materials. Epoxies are also used, although they require longer cure times and do not release easily from the pultrusion dies. Hence, thermosetting resins are most commonly used with pultrusion, although some high-performance thermoplastics such as PEEK and polysulfone can also be accommodated. In addition to the resin, the resin bath may contain a curing agent (initiator, cf. Section 3.3.1.2), colorants, ultraviolet stabilizer, and fire retardant. 

The first question to be discussed is the polymer miscibility which governs the blend morphology. The solubility parameters of BMIs is 12-135 (cal cm 3)0,5 vs. 11-12 (cal cm"3)0,5 for the high-performance thermoplastics [112]. We can expect an important non-miscibility however, the morphology will also depend on some other factors (conversion at the gel point, viscosity...) and as a result different types of morphologies were identified. 

A former application of aniline, now mainly displaced, was conversion to hydroquinone. The hydroquinone is the starting point for a process developed by Rose at ICI s Plastics Division. The outcome, a high melting polymer, resistant to oxidation, is poly(ether-ether-ketone), or PEEK, made from hydroquinone. This high-performance thermoplastic, with fiber reinforcements such as Kevlar, is used in plastic kettles, nose-cones of missiles and engines. 

Nylon-66, which was the classic high performance thermoplastic was produced by Carothers in the 1930 s by heating the purified salt produced by the reaction of adipic acid and hexa-methylenediamine. —) Over 125 thousand tons of these polyamides... 

In spite of their utility and versatility, the new high performance polymers will not displace general purpose thermoplastics, classic thermosets, ceramics or metals unless there is a demonstratable superiority. Fortunately, there are many applications for high performance thermoplastics for which no other material is adequate. Hence, the annual production of high performance thermoplastics in the late 1980 s will exceed the production of all plastics in the 1940 s. This unprecedented growth of these engineering polymers will be based entirely on their performance. 

Even when phase separation of a rubber such as CTBN or a HBP is optimized to produce an effective material, there will be the small fraction of the disperse phase that is soluble in the continuous phase, and trapped there at gelation. As noted earlier, this can affect the Tg if an elastomer is used, but is not a problem with the high-performance thermoplastics such as PES. 

This review summarizes our work at the University of Bayreuth over the last few years on improving the electret performance of the commodity polymer isotactic polypropylene (Sect. 3) and the commodity polymer blend system polystyrene/polyphenylene ether (Sect. 4) to provide electret materials based on inexpensive and easily processable polymers. To open up polymer materials for electret applications at elevated temperatures we concentrated our research on commercially available high performance thermoplastic polyetherimide resins and synthesized several fluorinaled polyetherimides to identify structure-property relations and to improve further the performance at elevated temperatures (Sect. 5). 

Kadel . [Amoco] Polyketone high performance thermoplastic for high temp, applies, in chemical processing, avia-tion/aerospace composites. 

Lenzing P84. [Lenzing AG] Aromatic polyimide high performance thermoplastic used fin prod, of needle felts for high temp, filtration, as reinforcement for FIFE, as competing, ingred. for inj. moldable polymers. ... 

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. 

PPO , that is, poly-2,6-dimethyl-l,4-phenylene ether or PPE, is a high-performance thermoplastic obtained by polymerization of DMP, which exhibits particular physical properties such as high thermal stability, elevated mechanical strength, and excellent hydrolytic stability (Table 7.1) [14]. 

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. 

Pont Valox 9730 developmental alloy of General Electric Victrex high-performance thermoplastics of ICI Mindel alloys of Amoco Performance Products, which combine various grades of sulfone polymers and Ryton PPS grades R-4 and R-7 of Phillips Petroleum Chemicals. 

Thermoplastic matrices, is particularly attractive for automotive applications PP, for example, is economical, it can be processed quickly and can provide much better mechanical properties such as impact resistance, (i.e., bumpers, body panels [11]). PA are successfully applied in both under hood (i.e., inlet manifolds, radiator fans) and interiors (instrument panels, doors, front-end structures). For better temperature performance and mechanical properties, in some special application areas (motor racing sector, gearbox parts), polyether ether ketone and polyphenylene sulfide ( high performance thermoplastics ) are also used as matrices. 

The major applications of LCP films in electronics are multilayer boards and multichip modules, and flexible printed circuits. Current materials used in the.se applications include polyimide film, high performance thermoplastic film such as polyphenylene sulfide and polyetherether ketone, and fiber reinforced composites such as quartz fiber-polyimide. The price of these materials for electronic packaging is in the range of. 50 to. l(K)/lb, so LCPs can compete very effectively at their current prices. Based on a two to three times increase in price... 

N.J. Johnston, High performance thermoplastics a review of neat... 

---