Polyphenylene sulfide general

At room temperature, polyphenylene sulfide generally resists most alcohols, aliphatic and aromatic hydrocarbons, greases, oils, gasoline, ketones, esters, ethers, glycols. 

As regards the general behaviour of polymers, it is widely recognised that crystalline plastics offer better environmental resistance than amorphous plastics. This is as a direct result of the different structural morphology of these two classes of material (see Appendix A). Therefore engineering plastics which are also crystalline e.g. Nylon 66 are at an immediate advantage because they can offer an attractive combination of load-bearing capability and an inherent chemical resistance. In this respect the arrival of crystalline plastics such as PEEK and polyphenylene sulfide (PPS) has set new standards in environmental resistance, albeit at a price. At room temperature there is no known solvent for PPS, and PEEK is only attacked by 98% sulphuric acid. 

Semi-aromatic PAs generally have a weak and slow absorption of water, a high rigidity, and are claimed to be more resistant to weathering and oils. For example, properties of polyphthalamides are intermediate between those of PA 66 and polyphenylene sulfide (PPS). 

At low temperatures, polyphenylene sulfide is used for cryogenic applications at -269°C. Generally, notched Izod impact strength does not significantly decrease between room temperature and -40°C. 

Uses Moth and bird repellent general insecticide, fumigant and germicide space odorant manufacture of 2,5-dichloroaniline and dyes pharmacy agriculture (fumigating soil) disinfectant, urinal deodorizer, air freshener, and chemical intermediate in the manufacture of 1,2,4-trichlorobenzene and polyphenylene sulfide. 

ETFE 8 General Purpose Polystyrene 6-9 HDPE 8 Impact Polystyrene 9 lonomer 8 LDPE 8 MDPE 8 Polyimide 7 Polymethylpentene 8 Polyphenylene Sulfide 8 Polypropylene 5-9 PVC 8 PVDC 7 SAN Copolymer 5-9 UHMWPE 8 Aluminum Chlorohydroxide elevated temoerature ... 

General Purpose Polystyrene lmp>act Polystyrene Polyphenylene Sulfide Polypropylene... 

General Purpose Polystyrene Impact Polystyrene Polyphenylene Sulfide SAN Copolymer... 

Many of the procedures used to prepare neutral CP precursors are commonly employed in the polymer industry. Hence, the polymerization methods of Ziegler-Natta, Friedel-Crafts, and nucleophilic displacements yield PA, PP, and polyphenylene sulfide (PPS), respectively. Other methods include Dields-Alder elimination, Wittig, and electrochemical coupling. The procedures used to prepare CPs in this vast arsenal are generally divided into two main categories chemical and electrochemical. 

Fortunately, the deficiencies of both the classic thermosets and general purpose thermoplastics have been overcome by the commercialization of a series of engineering plastics including polyacetals, polyamides, polycarbonate, polyphenylene oxide, polyaryl esters, polyaryl sulfones, polyphenylene sulfide, polyether ether ketones and polylmides. Many improvements in performance and processing of these new polymers may be anticipated through copolymerization, blending and the use of reinforcements. 

In the Phillips process, polyphenylene sulfide (PPS) is obtained from the polymerization mixture in the form of a fine white powder, which, after purification, is designated Ryton V PPS. Characterization of this polymer is complicated by its extreme insolubility in most solvents. At elevated temperatures, however, Ryton V PPS is soluble to a limited extent in some aromatic and chlorinated aromatic solvents and in certain heterocyclic compounds. The inherent viscosity, measured at 206°C in 1-chloronaphthalene, is generally 0.16, indicating only moderate molecular weight. The polymer is highly crystalline, as shown by x-ray diffraction studies (9). The crystalline melting point determined by differential thermal analysis is about 285°C. 

Macallum reported that polymers prepared in this manner generally contained more than one sulfur atom per repeat unit (x in the range 1.0-1.3) (2). In addition the polymerization reaction was highly exothermic and difficult to control even on a small scale (3). Later Lenz and co-workers at Dow reported another synthesis of PPS (4,5,6) based on a nucleophilic substitution reaction involving the self-condensation of materials such as copper p-bromothiophenoxide. The reaction was carried out at 200-250°C under nitrogen in the solid state or in the presence of a reaction medium such as pyridine. It was quite difficult to remove the by-product, copper bromide, from polymers made by this process (7). These and other methods of polymerization have been reviewed by Smith (8). Polyphenylene sulfide resins have been described more recently by Short and Hill (9). 

The range of Noryl blends 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 polycarbonates, polyphenylene sulfides, and polysulfones (discussed later). The materials that come close to them in properties are the... 

The term HT-thermoplastics is used for polymers, which in the absence of fillers, have a continuous-use temperature above approx. 200 °C. In contrast, standard plastics, such as PVC, polyethylene or polystyrene, have continuous-use temperatures of the order of 100 °C. In addition to their high temperature stability, HT-thermoplastics, in general, possess good resistance to chemicals and usually also low flammability. Among the most important HT-thermoplastics are polyphenylene sulfides (PPS), polysul-fones (PSU), polyether sulfones (PES), polyether imides (PEI), polyetherether ketones (PEEK) and polyarylates (PAR). 

Polyimide and polyphenylene sulfide (PPS) resins present a problem in that their high-temperature resistance generally requires that the adhesive have similar thermal proper-... 

Polyimide and polyphenylene sulfide resins present a problem in that their high temperature resistance generally requires that the adhesive have similar thermal properties. Thus, hi -temperature epoxies adhesive are most often used with polyimide and PPS parts. Joint strength is superior (greater than 1000 Ib/in ) but thermal resistance is not better than the best epo3 systems (300 to 400°F continuous). 

Figure P.17 General chemical structure of polyphenylene sulfide.

Engineering thermoplastic resins (ETP) are those whose set of properties (mechanical, thermal, chemical) allows them to be used in engineering applications. They are more expensive than commodity thermoplastics and generally include polyamides (PA), polycarbonate (PC), linear polyesters such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), polyphenylene ether (PPE) and polyoxymethylene (POM). Specialty resins show more specialized performance, often in terms of a continuous service temperature of 200°C or more and are significantly more expensive than engineering resins. This family include fluoropolymers, liquid crystal polymers (LCP), polyphenylene sulfide (PPS), aromatic polyamides (PARA), polysulfones (P ), polyimides and polyetherimides. 

Polyphenylene oxide (Noryl from GE) and polyphenylene sulfide (Ryton from Phillips) are used as high-temperature engineering plastics. Polyphenyl ether sulfones are manufactured by a number of companies under a variety of trade names including 720P, 220P by ICI and RADEL by Union Carbide. They are generally used as injection-moldable thermoplastics and in the adhesive and composite industry. 

Fortunately in the development of Ryton Polyphenylene Sulfide at Phillips Petroleum Company, all of the above factors were present throughout the project, thus contributing to its success. Once a new product becomes profitable, the same sort of backing is required to continue the growth of the market. However, this backing is generally easier to achieve since everyone likes a winner. 

The general-purpose thermoplastic polymers consist of such materials as polyethylene, polypropylene, polyurethanes, and polyvinyl chlorides. The engineering thermoplastic polymers include the polyimides, polyamideim-ide, polysulfones, polyetheretherketones, and polyphenylene sulfides. 

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