Polysulfone, bisphenol

Property Polysulfone (Bisphenol A) Polyether Sulfone Polyphenyl Sulfone... 

Extensive studies of the dynamic-mechanical properties of a number of different polysulfones has been reported by Robeson et al. [77] and by Aitken et al. [78] Most of studies reported in the literature have focused on the two commercially important polysulfones — bisphenol-A polysulfone (PSF)... 

Bisphenol A. One mole of acetone condenses with two moles of phenol to form bisphenol A [80-05-07] which is used mainly in the production of polycarbonate and epoxy resins. Polycarbonates (qv) are high strength plastics used widely in automotive appHcations and appHances, multilayer containers, and housing appHcations. Epoxy resins (qv) are used in fiber-reinforced larninates, for encapsulating electronic components, and in advanced composites for aircraft—aerospace and automotive appHcations. Bisphenol A is also used for the production of corrosion- and chemical-resistant polyester resins, polysulfone resins, polyetherimide resins, and polyarylate resins. 

Polysulfone. Polysulfone is a commercial polymer that is a product of bisphenol A and 1,1 -sulfonylbis (4-chlorobenzene) (see Polymers... 

The first aromatic sulfone polymer produced commercially was introduced as Bakelite polysulfone but now is sold by Union Carbide under the trade name Udel. It is made by reaction of the disodium salt of bisphenol A (BPA) with 4,4 -dichIorodiphenyl sulfone in a mixed solvent of chlorobenzene and dimethyl sulfoxide (eq. 12). 

The diphenylsulfone group is suppHed to the repeat unit of aU polysulfones by DCDPS the differentiating species between various polysulfones comes from the choice of bisphenol. There are three commercially important polysulfones referred to genericaHy by the common names polysulfone (PSF), polyethersulfone (PES), and polyphenylsulfone (PPSF). The repeat units of these polymers are shown in Table 1. 

Nucleophilic Substitution Route. Commercial synthesis of poly(arylethersulfone)s is accompHshed almost exclusively via the nucleophilic substitution polycondensation route. This synthesis route, discovered at Union Carbide in the early 1960s (3,4), involves reaction of the bisphenol of choice with 4,4 -dichlorodiphenylsulfone in a dipolar aprotic solvent in the presence of an alkaUbase. Examples of dipolar aprotic solvents include A/-methyl-2-pyrrohdinone (NMP), dimethyl acetamide (DMAc), sulfolane, and dimethyl sulfoxide (DMSO). Examples of suitable bases are sodium hydroxide, potassium hydroxide, and potassium carbonate. In the case of polysulfone (PSE) synthesis, the reaction is a two-step process in which the dialkah metal salt of bisphenol A (1) is first formed in situ from bisphenol A [80-05-7] by reaction with the base (eg, two molar equivalents of NaOH),... 

DMSO is an effective solvent for the polymerization as it affords good solubiUty for both the polymer and disodium bisphenol A [2444-90-8]. Typical polymerization temperatures for polysulfone are in the range 130—160°C. At temperatures below 130°C, the polymerization slows down considerably due to poor solubiUty of the disodium bisphenol A salt. 

Table 2. Glass-Transition Temperatures of Polysulfones Produced from the Polycondensation of Dichlorodiphenylsulfone with Various Bisphenols ...

These solvents include tetrahydrofuran (THF), 1,4-dioxane, chloroform, dichioromethane, and chloroben2ene. The relatively broad solubiHty characteristics of PSF have been key in the development of solution-based hoUow-fiber spinning processes in the manufacture of polysulfone asymmetric membranes (see Hollow-fibermembranes). The solvent Hst for PES and PPSF is short because of the propensity of these polymers to undergo solvent-induced crysta11i2ation in many solvents. When the PES stmcture contains a small proportion of a second bisphenol comonomer, as in the case of RADEL A (Amoco Corp.) polyethersulfone, solution stabiHtyis much improved over that of PES homopolymer. 

Bisphenol A is a solid material in the form of white flakes, insoluble in water but soluble in alcohols. As a phenolic compound, it reacts with strong alkaline solutions. Bisphenol A is an important monomer for producing epoxy resins, polycarbonates, and polysulfones. It is produced by the condensation reaction of acetone and phenol in the presence of HCI. (See Chapter 10, p. 273)... 

Scheme 6.11 Typical nucleophilic synthesis of bisphenol A polysulfone.

Quentin may have been the first to sulfonate (arylene ether sulfone).168 In this patent, it was demonstrated that the bisphenol A polysulfone could be sulfonated by chlorosulfonic acid to produce a sulfonated polyfarylene ether sulfone), which was used for desalination via reverse osmosis. However, the chlorosulfonic acid may be capable of cleaving the bisphenol A polysulfone partially at the iso-propylidene link or it might induce branching and crosslinking reactions by... 

Herbert and Hay reported a bisphenolic monomer, 3,8-bis(4-hydroxyphenyl)-A-phenyl-1,2-naphthalimide (Table 6.1), as well as its corresponding polyf V-phenyl imido aryl ether sulfone) via transimidization reactions with hydrazine monohydrate, aliphatic amines, and an amino acid.193 These polysulfones with... 

Hexa-fluorobisphenol A (HFBPA) based polysulfone and poly(arylene ether phosphine oxide) were prepared by nucleophilic aromatic substitution similar to that of bisphenol-A-based polysulfone and poly(arylene ether phosphine oxide).11... 

Bisphenol-A benzoxazine reaction, under acidic conditions, 416-417 Bisphenol-A polyarylates, 77 synthesis of, 109-113 Bisphenol-A polysulfone, 327 nucleophilic synthesis of, 337 Bisphenolic monomer, 354 Biurets, 227... 

Nucleophilic displacement, PQ and PPQ synthesis by, 310-311 Nucleophilic substitution, 10, 282, 283 hyperbranched polyimides via, 308 Nucleophilic synthesis, of bisphenol-A polysulfone, 337... 

Extraction or dissolution almost invariably will cause low-MW material in a polymer to be present to some extent in the solution to be chromatographed. Solvent peaks interfere especially in trace analysis solvent impurities also may interfere. For identification or determination of residual solvents in polymers it is mandatory to use solventless methods of analysis so as not to confuse solvents in which the sample is dissolved for analysis with residual solvents in the sample. Gas chromatographic methods for the analysis of some low-boiling substances in the manufacture of polyester polymers have been reviewed [129]. The contents of residual solvents (CH2C12, CgHsCI) and monomers (bisphenol A, dichlorodiphenyl sulfone) in commercial polycarbonates and polysulfones were determined. Also residual monomers in PVAc latices were analysed by GC methods [130]. GC was also... 

Sulfur dioxide was the major volatile product and was used as a probe to correlate the radiation resistance with polymer structure. The use of biphenol in the polymer reduced G(SO ) by 60% compared with bisphenol A based systems (Bis-A PSF). Surprisingly, the isopro-pylidene group was shown to be remarkably radiation resistant. The ultimate tensile strain decreased with dose for all polysulfones investigated and the rate of decrease correlated well with the order of radiation resistance determined from volatile product measurements. The fracture toughness (K ) of Bis-A PSF also decreased with irradiation dose, but the biphenol based system maintained its original ductility. 

SPSF-Na represents Bisphenol A-polysulfone which has been su3.fonated and... 

Polymer Preparation and Characterization. Bisphenol A-polysulfones of different molecular weight and sulfonated to various degrees have been prepared. In addition, the commercial Bis A-PSF has been sulfonated to various D.S. values and neutralized with sodium or potassium counter-ions. The... 

Polysulfones exhibit excellent thermal oxidative resistance, and resistance to hydrolysis and other industrial solvents, and creep. The initial commercial polysulfones were synthesized by the nucleophilic replacement of the chloride on bis(p-chlorophenyl) sulfone by the anhydrous sodium salt of bisphenol A. It became commercially available in 1966 under the trade name Udel. It exhibits a reasonably high Tg of 190°C. 

Union Carbide, in 1976, made available a second generation polysulfone under the trade name Radel. Radel was formed from the reaction of a bisphenol and bis(p-chlorophenyl) sulfone (structure 4.76). This polysulfone exhibits greater chemical and solvent resistance, greater Tg of 220°C, greater oxidative stability, and good toughness in comparison to Udel. 

Polymers XL-XLIII are commercially available. XL and XLI are referred to as poly-etheretherketone (PEEK) and polyetherketone (PEK), respectively. XLII and XLIII are known as bisphenol A polysulfone and poly ethersulf one, respectively. Polymers XLI and XLIII can be synthesized not only using the combination of A—A and B—B reactants, but also by the self-polymerization of appropriate A—B reactants. 

Figure 12. Variation of the yield of radicals determined by ESR with radiation dose for bisphenol-A aromatic polysulfone showing (D) dose saturation and ( ) effect of photobleaching.

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