Polysulfone formulae

The main difference between these entities is the thermal behaviour, which increases in the following order  

Polysulfones are appreciated for their good mechanical and electrical properties, rigidity, good creep behaviour, fatigue endurance, fair shrinkage and moisture uptake, broad range of service temperatures (-100 up to +150/200°C), optical and microwave transparency, fire resistance, suitability for food contact and sterilization. 

Polysulfones are handicapped by light and UV sensitivity requiring an efficient protection for outdoor exposure sensitivity to environmental stress cracking and attacks by chemicals such as aromatic hydrocarbons, chlorinated solvents and ketones the cost (justified by the performances) sometimes an insufficient fire resistance, but special grades are marketed. 

They can be classified according to the type of processing, specific properties and targeted applications  

The costs, as for all plastics, fluctuate greatly with the crude oil price, and are only given to provide a general idea. They are typically of the order of several Euros to a few tens of Euros per kilogram. 

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Polysulfone Resins. Commercially important polysulfones are aromatic, ie, in the generalized formula for the repeating unit R and R both contain aromatic rings (see Polymers containing sulfur, polysulfone resins). They all possess ether linkages as weU, so that use of the designations polysulfone, polyarylsulfone (PAS), and polyethersulfone (PES) is somewhat arbitrary. 

In addition, some polysulfones are modified to produce materials with specific properties. Figure 4.97 shows examples of formulae. 

Bisphenol A, (CH3)2C(CjH40H)2, is made up of white flakes that have a mild phenolic odor. It is insoluble in water. Bisphenol A is combustible, with a flash point of 175T. It is not hsted in the DOT Hazardous Materials Tables. It is used in the manufacture of epoxy, polycarbonate, polysulfone, and polyester resins, as a flame retardant, and as a fungicide. The structure and molecular formula are shown in Figure 11.2. 

Today, the widely used aromatic polysulfones as constmctional and elec-troisolating materials are those of general formula [-0-Ar-S02-] where R stands for aromatic radical. 

Borax Einope and US Borax sell hydrated zinc borate flame retardants under the Firebrake name. Firebrake ZB is an example it has the formula 2ZnO.3B2O3.5H2O and the average particle size is seven microns. Firebrake 500 withstands high temperatures because it consists of anhydrous zinc borate, with no water to lose. It can be used in polyetherketones, polysulfones, fluoropolymers, polyesters and polyamides. It has a very beneficial effect on the heat release rate, suppresses smoke and afterglow, as well as promoting char. It is recommended for aircraft applications. 

While most of noncellulosic membranes rely on the selectivity of glassy polymers such as polysulfone, the Ube Gas Separation System is based on poly-imide produced by condensation polymerization of biphenyltetracarboxylic di-anhydride and aromatic diamines. The chemical formula of the polymeric ma-... 

In the polysubstitution of naphthalene the sulfo groups are never found ortho, para, or peri (1,8) to one another even so, six disulfonic acids, three trisulfonic acids, and one tetrasulfonic acid are obtainable by sulfonation reactions. Seventy-three polysulfonic acids are theoretically possible. The acids obtainable from naphthalene by sulfonation are indicated in the chart the symbol S used in the formulas represents the sulfonic acid group. 

In the first stage, up to 10% of carbon is removed with carbon oxides. Relation of this percent to the content of anomalous structures in the polymer indicates that different structure degree is too high, much higher than the sensitivity of spectral methods. Meanwhile, preliminary analyses of studied thermoresistant polymeric materials (TP) showed their correspondence to postulated formulae, i.e. PSF corresponds to bisphenol A-derived polysulfone structure, PAl corresponds to fatty-aromatic polyimide derived fi om PPA and dodecamethylene diamine, etc. 

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