Clear engineering thermoplastics

Transparent (clear) engineering thermoplastics are used increasingly for medical, automotive, and architectural products windows, skylights, panels compact disks, fiber-optics sleeves lenses, reflectors, and light transmission pipes. ASTM D1003 (ISO 14782/13468), Haze and Luminous Transmittance of Transparent Plastics (Hazemeter or Spectrometer), describes optical properties of thermoplastics. 

The absence of polar groups along the polymer chain results in a low dielectric constant with respect to other common engineering thermoplastics. This represents a clear advantage in electric and electronic applications, but also has useful consequences in processing operations where a low moisture adsorption leads to short drying cycles (or none). 

At least two good ways out exist. One consists of the dispersion at the molecular level of rigid polymer molecules between flexible chains - the concept of molecular composites of Helminiak, Hwang e.a.(2, 4j. The other involves the use of polymer liquid crystals (PLCs). As discussed by Witt (5), compared to widely used engineering thermoplastics, PLCs show clear... 

Shell http //www.sheiichemicais.com] Traytuf 80541[Goodyear http //WWW.goodyearchemicai. com] Traytuf 9506 t[Shell http //www.sheiichemicais.com] Traytuf Ultra-Clear t[Goodyear http //www.goodyearchemicai.com] Ultralen SP t[BASF AG http //www.basf.de] Ultralen SP 3700 S t[BASF AG http //www.basf.de] Ultralen SP 3705 t[BASF AG http //www.basf.de] Vybex 40005 BLUT t[Ferro/Engineering Thermoplastics]... 

From a survey of the recent development in the field of self reinforcing polymers it appears clearly that the unique properties of the LCP make them primary candidates as reinforcing agent, added to engineering thermoplastic in the form of second phase. In the design of the blend several parameters have to be considered, but first let consider in close details the major features of liquid-crystalline compounds. 

PROPERTIES OF SPECIAL INTEREST Polycarbonate engineering thermoplastics are amorphous, clear polymers that exhibit superior dimensional stability, good electrical properties, good thermal stability, and outstanding impact strength. They... 

The liquid crystalline polymers find more applications in smart composite materials. The popularity of LCP is growing very fast because of its ease of processing. It also helps other engineering thermoplastics to process very smoothly even at higher temperature. This happens mainly due to the fibril formations of LCP in presence of other polymer matrix. From the above mentioned areas of LCPs, it is clear that new results arise due to the incorporatiOTi of polymeric LCP in to the other polymer systems. It is very much clear that in future it will create its own vast area in the field of polymer blends and nanocomposites. 

Isoplast engineering thermoplastic polyurethane resins of Dow [15] combine the toughness and dimensional stability of amorphous resins with the superior performance and chemical resistance associated with semicrystalline resins. Isoplast is available in impact-modified, clear and glass-reinforced resins, with a range of options to meet the most demanding applications. Table 15 gives descriptions and applications of Isoplast TPE-U products. 

As compared to usual engineering thermoplastics, PLCs show clear superiority with regard to chemical stability. 

Many thermoplastics are now accepted as engineering materials and some are distinguished by the loose description engineering plastics. The term probably originated as a classiflcation distinguishing those that could be substituted satisfactorily for metals such as aluminium in small devices and structures from those with inadequate mechanical properties. This demarcation is clearly artificial because the properties on which it is based are very sensitive to the ambient temperature, so that a thermoplastic might be a satisfactory substitute for a metal at a particular temperature and an unsatisfactory substitute at a different one. 

Clearly thermoplastic starch based polymers offer a very attractive base for new biodegradable polymers due to their low material cost and ability to be processed on conventional plastic processing equipment. The engineering of more advanced properties into these low cost base materials will continue to be... 

The nylon market can be divided into two segments resin products and fibre products. The total consumption of nylon in Western Europe was 913,000 tons in 1993, of which 560,000 tons were fibre products divided among textiles, carpets, and industrial fibre [22]. The total annual nylon consumption, as well as that of other engineering plastics, is small compared to that of high-volume commodity thermoplastics for example, the consumption of LLDPE/LDPE for 1993 was 5,548,000 tons [22]. Engineering plastics therefore constitute a minor share of the total plastics waste. Nevertheless, for an environmentally responsible company it is necessary to develop a clear strategy for the recycling of products and to help their clients do the same. 

Silicone-polycarbonate co-polymer n. Introduced in 1969 by the General Electric Co., these thermoplastic co-polymers vary from strong elastomers to rigid engineering plastics, depending on composition. They can be extruded, cast, or molded into optically clear films. 

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