Polyphenylene Sulphides

The polyetherimides are competitive not only with other high-performance polymers such as the polysulphones and polyketones but also with polyphenylene sulphides, polyarylates, polyamide-imides and the polycarbonates. 

The successful development of polyfethylene terephthalate) fibres such as Dacron and Terylene stimulated extensive research into other polymers containing p-phenylene groups in the main chain. This led to not only the now well-established polycarbonates (see Chapter 20) but also to a wide range of other materials. These include the aromatic polyamides (already considered in Chapter 18), the polyphenylene ethers, the polyphenylene sulphides, the polysulphones and a range of linear aromatic polyesters. 

The range of blends now available comprises a broad spectrum of materials superior in many respects, particularly heat deformation resistance, to the general purpose thermoplastics but at a lower price than the more heat-resistant materials such as the polycarbonates, polyphenylene sulphides and polysulphones. At the present time the materials that come closest to them in properties are the ABS/ polycarbonate blends. Some typical properties are given in Table 21.1. 

Over the years polymers have been produced suitable for use at progressively higher temperatures. Where this is a requirement, it is usual first to decide whether a rubbery or a rigid material is required. If the former, this has been dealt with by the author elsewhere." If the latter, it is usually convenient to look in turn at polycarbonates, PPO-based materials, polyphenylene sulphides, polysul-phones, polyketones such as PEEK and PEK, polyamide-imides, poly-phthalamides, fluoropolymers, liquid crystal polymers and polyimides. 

Some self-lubricating grades of polyphenylene sulphide, containing specific additives and reinforced with glass or carbon fibres, are marketed. The coefficients of friction are good, for example 0.2 for a carbon fibre reinforced compound. 

Polyphenylene sulphide (PPS) (e.g. Ryton ) is a highly crystalline polymer with a melting point of 290 °C. It combines good mechanical properties with very high thermal and chemical resistance it is, moreover, self-extinguishing. It is, i.a., used as protective coating on metal surfaces. 

The preparation of polyphenylene sulphides from p-halothiophenols also involves a difference in the reactivity of end groups on monomers, compared to those on the ends of polymer chains (fei k2), the processes being... 

The structural analysis using high resolution solid-state NMR has been successfully performed on other conducting polymers such as polyphenylene vinylene [21], polyaniline [22-24], polyphenylene sulphide [25, 26] and poly-p-phenylene [27-29]. 

A comprehensive study of the thermal degradation of epoxy resins has been reported by Lee [239]. Their stability was found to be lower than that of polycarbonate, polyphenylene sulphide and teflon (Fig. 64). 

M. Lambla, R. Mestanza, D.-J. Lin, E. Vandevijver, andM.-P. Collard. Polyphenylene sulphide-based compositions with improved impact strength and process for preparing them. US Patent 6 849 697, assigned to Solvay Polyolefins, S.A. (Brussels, BE), February 1, 2005. 

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