Engineering plastics performances

Performance Chemicals Chemical Intermediates Engineering Plastics Performance Rubber... 

In fact, technology developments emerging through alloys, blends and con osites are likely to be the major factor driving engineering plastics performance toward metals equivalency and a market opportunity delineated by the Fisher-Pry substitution theory to be as much as 18 billion pounds annually by the year 2000.1... 

Engineering plastics perform for prolonged use in structural applications over a wide range of temperature under mechanical stress and in difficult chemical and physical environments. These properties are either advantages or disadvantages, depending on use. 

Acrylic ESTER POLYMERS Acrylonitrile POLYMERS Cellulose esters). Engineering plastics (qv) such as acetal resins (qv), polyamides (qv), polycarbonate (qv), polyesters (qv), and poly(phenylene sulfide), and advanced materials such as Hquid crystal polymers, polysulfone, and polyetheretherketone are used in high performance appHcations they are processed at higher temperatures than their commodity counterparts (see Polymers containing sulfur). 

In recent years a whole new generation of high performance engineering plastics have become commercially available. These offer properties far superior to anything available so far, particularly in regard to high temperature performance, and they open the door to completely new types of application for plastics. 

Kemmish, D.J. High performance engineering plastics, RAPRA Review Reports, 8, 2 (1995) Oswald, T.A. and Menges, G. Materials Science of Polymers for Engineers, Hanser, Munich (1995)... 

Strong elongational deformation and use of matrix polymers whose viscosity is higher than that of TLCP phase are better to ensure uniform and fine fibril formation. But application of compatibilizing techniques to in situ composite preparation can be useful to get the most desirable products. These can reduce the high costs of the liquid crystalline polymers and expensive special engineering plastics used for the in situ composite preparation and reduce the processing cost, whereas they can increase the performance of produced in situ composites, hence, their applications, too. 

Plastic also refers to a material that has a physical characteristic such as plasticity and toughness. The general term commodity plastic, engineering plastic, advanced plastic, advanced reinforced plastic, or advanced plastic composite is used to indicate different performance materials. These terms and others will be reviewed latter in this chapter. Plastics are made into specialty products that have developed into major markets. An example is plastic foams that can provide flexibility to rigidity as well as other desired properties (heat and electrical insulation, toughness, filtration, etc.). 

In addition to the broad categories of TPs and TSs, TPs can be further classified in terms of their structure, as either crystalline, amorphous, or liquid crystalline. Other classes (terms) include elastomers, copolymers, compounds, commodity resins, engineering plastics, or neat plastics. Additives, fillers, and reinforcements are other classifications that relate directly to plastics properties and performance. 

The pace of development has increased with the commercialization of more engineering plastics and high performance plastics that were developed for load-bearing applications, functional products, and products with tailored property distributions. Polycarbonate compact discs, for example, are molded into a very simple shape, but upon characterization reveal a distribution of highly complex optical properties requiring extremely tight dimension and tolerance controls (3,223). 

Another method of reducing the quantity of plastics that has been used in certain products is to use engineered plastics with higher performance than the lower-cost commodity plastics. When applicable, this approach permits using less material to compensate for its higher cost. With a thinner-walled construction there could also be additional cost savings, since less processing heat, pressure, and time cycle is required. 

Report 86 High Performance Engineering Plastics, D.J. Kemmish, Victrex Ltd. Report 113 Rubber-Modified Thermoplastics, H. Keskkula, University of Texas at Austin. 

Poly(2,6-dimethyl-l,4-oxyphenylene) (poly(phenylene oxide), PPG) is a material widely used as high-performance engineering plastics, thanks to its excellent chemical and physical properties, e.g., a high 7 (ca. 210°C) and mechanically tough property. PPO was first prepared from 2,6-dimethylphenol monomer using a copper/amine catalyst system. 2,6-Dimethylphenol was also polymerized via HRP catalysis to give a polymer exclusively consisting of 1,4-oxyphenylene unit, while small amounts of Mannich-base and 3,5,3, 5 -tetramethyl-4,4 -diphenoquinone units are always contained in the chemically prepared PPO. 

Report 86 High Performance Engineering Plastics, D.J. Kemmish, Victrex Ltd. 

Polyimides are engineering plastics used only for specialized and technical applications. The applications are always high-tech. The price and the difficulty of transformation limit the use of polyimides to well-targeted applications taking advantage of the high performance of these materials. 

The properties of unidirectional composites in the fibre direction can compete with those of current metals and alloys. The highest-performance engineering plastics compete with magnesium and aluminium alloys. 

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