High Performance Applications

In 2004, Sony and Mitsubishi Plastics teamed up to develop a flame retardant PLA biodegradable resin claimed to be as strong as ABS. The new material will be used in the front panel of Sony standalone DVD players. The resin employs an aluminium hydroxide flame retardant, is rated UL94 V-2 and complies with the EU s Restrictions on Hazardous Substances (RoHS) directive. Sony says the use of additives and modifications to moulding parameters allows it to process PLA compound on conventional injection presses in commercially viable cycle times. 

Toyota Tsusho Corp., a subsidiary of Toyota Corp, and Diversified Natural Products Inc, of the USA, formed a partnership in 2004 to explore the use of PLA in automotive applications. 

Pioneer Corp. of Japan has used PLA as a replacement for polycarbonate to manufacture an optical disc. 

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Applied Sciences, Inc. has, in the past few years, used the fixed catalyst fiber to fabricate and analyze VGCF-reinforced composites which could be candidate materials for thermal management substrates in high density, high power electronic devices and space power system radiator fins and high performance applications such as plasma facing components in experimental nuclear fusion reactors. These composites include carbon/carbon (CC) composites, polymer matrix composites, and metal matrix composites (MMC). Measurements have been made of thermal conductivity, coefficient of thermal expansion (CTE), tensile strength, and tensile modulus. Representative results are described below. 

One may now ask whether natural systems have the necessary structural evolution needed to incorporate high-performance properties. An attempt is made here to compare the structure of some of the advanced polymers with a few natural polymers. Figure 1 gives the cross-sectional microstructure of a liquid crystalline (LC) copolyester, an advanced polymer with high-performance applications [33]. A hierarchically ordered arrangement of fibrils can be seen. This is compared with the microstructure of a tendon [5] (Fig. 2). The complexity and higher order of molecular arrangement of natural materi-... 

Since the 1930s, the TP pipe industry continues to expand its use worldwide. It now represents over 30% of the dollar share compared to other materials (iron/steel at 45%, copper at 12%, concrete at 8%, aluminum at 4%, etc.). Although RP TS pipe represents a small portion of the market, it is a product of choice for many special high performance applications. Corrosion resistance, toughness, and strength contribute to its growing acceptance. 

Polyetheretherketone PEEK is a high-temperature, crystalline engineering TP used for high performance applications such as wire and cable for aerospace applications, military hardware, oil wells and nuclear plants. It holds up well under continuous 450°F (323° C) temperatures with up to 600°F (316° C) limited use. Fire resistance rating is UL 94 V-0 it resists abrasion and long-term mechanical loads. 

An indication of the usefulness of polyurethanes can be found in worldwide consumption data as of 2000, urethanes of all types amounted to 9.25 million tons.10 The commercial success of urethane polymers can be attributed to the ability to conveniently manufacture and apply materials with specific combinations of physical properties. Furthermore, urethanes are often the best choice in demanding, high-performance applications. In this section, the applications listed in Table 4.1 are discussed and a few examples are given from each category. 

Aqueous, removable, pressure-sensitive adhesive compositions, useful for high-performance applications, comprise a mixture of a copolymer of alkyl (meth)acrylate and N-substituted (poly)amide of (meth)acrylic acid and a copolymer of alkyl (meth)acrylate and ethylenically unsaturated carboxylic acid, where at least one of the copolymers is an emulsion copolymer. Polyoxyalkyl-enes and phosphate esters may be used as surfactants [234]. 

Though short fiber-reinforced mbber composites find application in hose, belt, tires, and automotives [57,98,133,164] recent attention has been focused on the suitability of such composites in high-performance applications. One of the most important recent applications of short fiber-mbber composite is as thermal insulators where the material will protect the metallic casing by undergoing a process called ablation, which is described in a broad sense as the sacrificial removal of material to protect stmcrnres subjected to high rates of heat transfer [190]. Fiber-reinforced polymer composites are potential ablative materials because of their high specific heat, low thermal conductivity, and ability of the fiber to retain the char formed during ablation [191-194]. 

Economy, /. and Goranov, K. Thermotropic Liquid Crystalline Polymers for High Performance Applications. Vol. 117, pp. 221 -256. 

As mentioned earlier, siloxanes impart a number of beneficial properties to polymeric systems into which they are incorporated, including enhanced solubility, resistance to degradation in aggressive oxygen environments, impact resistance and modified surface properties. These particular advantages render polysiloxane-modified polyimides attractive for aerospace, microelectronic and other high performance applications (40-43). 

Fluoropolymers, too, while traditionally associated with extreme high-performance applications have found their way into our homes, our clothing, and even our language. A recent American president was often likened to the tribology ofPTFE. 

The thermal stability and lightfastness of polyesters is particularly necessary for technical and high-performance applications. The modification of the polymer causes disorder and affects the stability as well as some other properties. PET modified by DEG suffers particularly from photo-oxidative reactions due to the presence of the sensitive ether bonds. These copolymers need special stabilization depending on the kind and degree of modification. The UV stability can also be influenced by the technology of the process, whereby slight improvements of DMT-based polymer are observed [29],... 

Ruorinated thermoplastics are only used for high-performance applications related to their high heat, low temperature, chemical inertness, high purity, non-stick and self-lubricating properties. High-purity grades are appreciated by the semiconductor, pharmaceutical and other similar sectors. 

ETFEs are only used for relatively high-performance applications related to heat, low temperature, chemical inertness and electrical insulation. 

PCTFEs are only used for high-performance applications requiring gas barrier effects, low temperatures, chemical inertness, electrical insulation. 

The polyimides are typical polymers for very-high-performance applications. 

Mat and continuous glass fibre reinforcements theoretically all the thermoplastics are usable in these forms, but up to now developments have concentrated on polypropylenes (PP), polyamides (PA) and thermoplastic polyesters (PET) fibre-reinforced PEEK, polyetherimide (PEI) and polyphenylene sulfide (PPS) are used for high-performance applications. They are presented in a range of forms from stampable sheets to pellets, prepregs, ribbons, impregnated or coated continuous fibre rods. More rarely (as in the case of PA 12, for example), the thermoplastic is provided in liquid form. 

Intended for high-performance applications because of their cost, carbon fibres have excellent mechanical properties but are sensitive to impact and abrasion. They are used for their attractive characteristics, such as ... 

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