Polyether sulfones

Polyether sulfones (PES) are another class of engineering thermoplastics generally used for objects that require continuous use of temperatures around 200°C. They can also be used at low temperatures with no change in their physical properties. 

Properties of polycarbonates compared with some thermoplastics  

Resin Melting or glass transition tensile temperature strength (X) (MPa) compressive strength (MPa) flexural strength (MPa) Izod impact, 1/8 in. (J/m) 

Polyether sulfones can be prepared by the reaction of the sodium or potassium salt of bisphenol A and 4,4-dichlorodiphenyl sulfone. Bisphenol A acts as a nucleophile in the presence of the deactivated aromatic ring of the dichlorophenylsulfone. The reaction may also be catalyzed with Friedel-Crafts catalysts the dichlorophenyl sulfone acts as an electrophile  

Polyether sulfones could also be prepared using one monomer  

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Recently, Dutta and Maiti [21] reported nitro displacement polymerization of the bisphenol dianion with the sulfone activated dinitro aromatic compounds. In addition, there have been recent reports of the development of functionalized PEEK [22] and polyether sulfone ketone (PESK) [23] that are comparable to commercially available high performance polymers. 

Table 11 describes the thermal properties of polyether sulfone based on DCDPS and heteroarylenediol. The TgS range from 230 to 315°C and the decomposition temperature is higher than 450°C. Their thermal stability depends on the bisphenol and activated difluoride used in the polymer synthesis (Tables 10 and 11). 

Table 11 Tg and Thermal Stability of Polyether Sulfone Synthesized by Displacement Reaction...

In general, properties of polyether sulfones are similar to those of polycarbonates, but they can be used at higher temperatures. Figure 12-6 shows the maximum use temperature for several thermoplastics. Aromatic polyether sulfones can be extruded into thin films and foil and injection molded into various objects that need high-temperature stability. 

Note Glass filler can considerably extend the performance of the above polymers. PEI = polyetherimide PES = polyether sulfone PPS = polyphenylene sulfide PSF = polysulfone PC = polycarbonate. 

POLYSULFONE POLYETHER SULFONE THIN SECTION (0.001 TO 0.050 IN.) POLYETHYLENE POLYPROPYLENE POLYVINYLS POLYBUTYLENES IONOMER... 

Thermoplastics for aircraft interiors have been evaluated by this technique (10b) in accordance with the FAA specification (peak rate of heat release of 65 kilowatts per meter squared (Kw/m 2) or less). In these tests (10b) Polyether sulfone demonstrated marginal compliance. For Polyether imide (PHI) and PEI/Polydimethyl siloxane copolymers peak heat-release rates were well below the specified value. The overall trend suggested a possible correlation of peak heat release values with aromatic carbon content in the polymers evaluated. 

Fracture toughness may correlate with the 0 relaxation temperature for the polymer. After irradiation, the 0 relaxation temperature increases with a corresponding broadening and decrease in intensity which can be seen in Figure 1. This result is consistent with the results of Hinkley et. al. (13) who observed the same phenomenon for polyether sulfone irradiated with electron beam irradiation above Tg. 

The most successful class of thermally reactive oligomers consists of the functional polymers containing either pendant or terminal triple bonds, especially ethynyl groups. This area of research was recently reviewed (2), and the more recent developments in the field of a,w-bis(ethynylpheny1) aromatic polyether sulfones were summarized in two recent papers (5,6). 

This paper reviews some of our work on general methods for the synthesis of polyaromatics containing either terminal or pendant styrene groups and their thermal polymerization. The examples provided in this paper refer to an aromatic polyether sulfone (PSU) and poly-(2,6-dimethy1-1,4-phenylene oxide) (PPO). 

Figure la. 200 MHz H-NMR spectrum (CDCl IMS) of a, -d1(bromobenzyl) aromatic polyether sulfone (PSU) from Scheme 4. 

An example for the synthesis of poly(2,6-dimethyl-l,4-phenylene oxide) - aromatic poly(ether-sulfone) - poly(2,6-dimethyl-1,4-pheny-lene oxide) ABA triblock copolymer is presented in Scheme 6. Quantitative etherification of the two polymer chain ends has been accomplished under mild reaction conditions detailed elsewhere(11). Figure 4 presents the 200 MHz Ir-NMR spectra of the co-(2,6-dimethyl-phenol) poly(2,6-dimethyl-l,4-phenylene oxide), of the 01, w-di(chloroally) aromatic polyether sulfone and of the obtained ABA triblock copolymers as convincing evidence for the quantitative reaction of the parent pol3rmers chain ends. Additional evidence for the very clean synthetic procedure comes from the gel permeation chromatograms of the two starting oligomers and of the obtained ABA triblock copolymer presented in Figure 5. 

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