Engineering thermoplastics examples

Surface Treatment—Engineering Thermoplastics (Examples of Representative Commercial Materials). 

An example of a sulfite ester made from thionyl chloride is the commercial iasecticide endosulfan [115-29-7]. A stepwise reaction of thionyl chloride with two different alcohols yields the commercial miticide, propaigite [2312-35-8] (189). Thionyl chloride also has appHcations as a co-reactant ia sulfonations and chlorosulfonations. A patent describes the use of thionyl chloride ia the preparation of a key iatermediate, bis(4-chlorophenyl) sulfone [80-07-9] which is used to make a commercial polysulfone engineering thermoplastic (see Polymers CONTAINING SULFUR, POLYSULFONe) (190). The sulfone group is derived from chlorosulfonic acid the thionyl chloride may be considered a co-reactant which removes water (see Sulfolanes and sulfones). 

Extmded engineering thermoplastic stock can be treated like other building material ia that it can be machined, cut, and fastened. However, none of the engineering plastics can be considered a one-for-one substitute for metals or wood. For example, impact resistance must be considered, and glues, paints, etc, must be screened for chemical aggressiveness and adhesion capabiUty. 

Engineering thermoplastics have also been used ia preimpregaated coastmctioas. The thermoplastic is thoroughly dispersed as a coatiauous phase ia glass, other resias, carboa fibers (qv), or other reinforcement. Articles can be produced from these constmctions usiag thermoforming techaiques. For example, the aerospace iadustry uses polyetheretherketoae (PEEK) ia wovea carboa-fiber tapes (26). Experimental uses of other composite coastmctioas have beea reported (27) (see also Composite materials, polymer-matrix). 

Commercial engineering thermoplastic nylons are mainly crystalline resins. Nylon-6,6 [32131 -17-2] is the largest volume resin, followed by nylon-6 (48). Other commercially available but much lower volume crystalline nylons are -6,9, -6,10, -6,12, -11, and -12. The crystallinity of the molded part decreases with chain size (49). A few truly amorphous commercial nylon resins contain both aromatic and ahphatic monomer constituents (50). For example, Trogamid T resin is made from a mixture of 2,2,4- and 2,4,4-trimethylhexamethylenediamines and terephthahc acid (51). 

Figure 1. Examples of repeating unit in advanced engineering thermoplastics.

It is well known that char formation during polymer burning is an important mechanism by which polymers resist burning. For example Van Krevelen (1-2) has shown that a correlation exists between the oxygen index (OI) of a polymer containing no heteroelements and the amount of char it forms when pyrolyzed in the absence of air. As shown in Table I, a similar correlation is seen to hold for a number of common engineering thermoplastics. 

Saturated complex polyesters, particularly, poly (butylene terephthalate) (PBT) are used as engineering thermoplastics possesing good thermo - and wearstability, excellent moulding. These properties also allow to use them as matrix material for polymer composites [1], One of the perspective ways of search of effective catalysts for such systems is kinetic study of the reesterification model reaction, performed in the presence of various catalysts and comparison it with the results of the similar reaction without catalyst. Clarification on the example of model system of the most effective catalysts list allows to use them for obtaining both filled and nonfilled PBT and compare catalytic activity of various catalysts. The purpose of the... 

Table 2.18 Examples of UL94 VO gl s fibre remforced engineering thermoplastics...

Connectors, switches, electric distributors, fuse boxes and other electric fittings need a subtle balance of electrical and mechanical properties, durability, cost and aesthetics. This broad field creates fierce competition not only between engineering thermoplastics and SMC/BMC for the main applications but also with polypropylene and polyethylene or PVC for the lower performance parts and, at the opposite end of the scale, with high-tech plastics such as polyetherketone, polyetherimide, liquid crystal polymers. .. For example, without claiming to be exhaustive ... 

Let us quote some mechanical engineering application examples for some thermoplastics. These examples can be commercialized, in development, potential or related to very specific uses. The designer must verify the possibility to use the quoted thermoplastic family for a specific problem and test the right grade under real service life conditions. 

Higher costs are acceptable if particular properties are obtained. For example, engineering thermoplastics such as modified and reinforced polyamides can be used for demanding and top-of-the-range applications. 

There are numerous studies and some industrialization of fibre reinforced engineering thermoplastic uses in aeronautics, for example ... 

Engineering Thermoplastics Polyolefins and Styrenics Table 3.4 Examples of commercially available UHMWPEs... 

Pipe and fittings, a principal market for PVC, are a prime example of PVC as an engineering thermoplastic. 

Performance requirements for other large plastic parts like fascia, hoods, and deck Hds would most likely eliminate one or another of these polymers and/or molding processes from consideration. For example, SMC 1s not considered to have sufficient Impact resistance for fascia and RIM and engineering thermoplastic materials have yet to be developed for structural applications which also require a high surface quality, 1.e. hoods and deck lids. These other parts were thus not chosen for this study. 

For example, a) Page, I. B. Polyamides as Engineering Thermoplastic Materials , Rapra Review Report, Vol. 11, No. 1, Report 121, 2000. b) SteinbUchel, A. Rhee, S. K. (Eds.), Polysaccharides and Polyamides in the Food Industry. Properties, Production, and Patents. Wiley-VCH, Weinheim, 2005,... 

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