Polysulfone

Polysulfone, Udel —Solvay Advance Polymers, www.solvayadvancedpolymers.com, is a thermoplastic resin with very high strength and has one of the highest service temperatures (171 °C) of any 

Another method using a grit-blast and ultrasonic cleaning, was used by General Electric. In this method, polysulfone parts were prepared for bonding to niobium with AF-42 epoxy-nylon film adhesive (3M Co). The procedure is as follows  

Grit-blast with 27—50 micron aluminum oxide (AI2O3). Use S.S. White Airbrasive Equipment, or equivalent, available from S.S. White Industrial Products, Piscataway, NJ 

Other methods include vapor degreasing in methanol, sanding or vapor blasting, and alcohol-wipe and/or light sanding, plus vinyl, urethane, or silicone primer. 

Used at temperatures up to 140°C, polysulfone has good resistance to aqueous solutions of acids and alkalis it is satisfactory with aliphatic solvents but is swollen by aromatics and stress cracked by several organic solvents, including acetone, ethyl acetate, trichlorethylene and carbon tetrachloride. 

A production of transparent articles from polysulfone required addition of plasticizer to polysulfone that was specially purified to remove certain reaction impurities. Plasticizer is added to improve film flexibility. Plasticizers having high compatibility with polysulfone include diethyl phthalate, benzyl butyl phthalate, tricresyl phosphate, and methyl phthalyl ethyl glycolate. Up to 30 wt% of plasticizer can be used but usually 10 wt% of plasticizer is added.  

Compressed CO2 and N2O plasticize polysulfone. N2O is more polar than CO2 and it is slightly more effective in plasticization of polysulfone.  

To overcome the disadvantages of nylon as an engineering material-high water absorption and poor creep strength at elevated temperatures—many newer polymers were developed. Table 3.47 lists polymers that are among the most commercially important acetal, polycarbonate, polyphenylene oxide and polysulfone. 

This has the same stiffness as dry nylon but absorbs less than one-fifth the amount of water and retains its strength and shape in humid conditions at considerably higher temperatures. Acetal has poor resistance to aqueous solutions of strong acids and should not be used at a pH below 3. The acetal s copolymers are satisfactory in most alkaline conditions. All grades have very good resistance to mineral oils and petrols and to most organic solvents including chlorinated compounds. 

This has a very high resistance to impact damage, even at subzero temperatures. It has good creep strength in dry conditions up to 115°C but degrades by continuous exposures to water hotter than 65°C. It is resistant to aqueous solutions of acids, aliphatic hydrocarbons, paraffins, alcohols (except methanol), animal and vegetable fats and oils, but is attacked by alkalis, ammonia, aromatic and chlorinated hydrocarbons. 

A stable material in humid conditions at temperatures up to 105°C, polyphenylene oxide is resistant to most aqueous solutions of acids and alkalis but is attacked by many organic solvents, particularly by aromatics and chlorinated aliphatics. 

Major polymer applications tubing, in medical applications which require resistance to hot water and sterilization, microwave cookware, printed circuit boards 

Important processing methods injection molding, blow molding, extrusion, thennoforming 

Typical fillers glass fiber, carbon fiber, aramid fiber, PTFE 

Typical concentration range glass fiber - 20-30 wt%, PTFE - 8-15 wt% 

Special considerations material should have a moisture content below 0.05% to prevent bubbling, surface streaks, etc. 

The polymers are stable in aqueous inorganic acids, alkalis, salt solutions, aliphatic hydrocarbons, and paraffin oils, are transparent, capable of steam sterilization, and free from taste and smell. They should not 

Blow film extrusion Flat film extrusion Blow moulding Thermoforming Compression moulding 

Injection moulding Extrusion Blow moulding Compression moulding Thermoforming 

No pre-drying treatment except hygroscopic additives are added. 

Adhesives recommended by the manufacturer. Union Carbide, include  

Scotch-Grip 880 one-part solvent-based chloroprene Scotch-Weld 1838 two-part epoxy Scotch-Weld 2214 one-part epoxy Scotch-Weld 2216 two-part epoxy 

BR-92 two-part epoxy with either DICY curing agent or curing agent Z 

Uralane 5738 two-part polyurethane Uralane 8615 two-part polyurethane 

The Scotch-Grip 880 elastomeric adhesive is recommended for bonding polysulfone to canvas, and Uralane 8615 for bonding polysulfone to polyethylene. 

Exposure medium Exp. medium note Cone. (%) Temp. Time PDL Resistance note % Change % Retained Test note Material note 

Accelerated Weathering xenon-arc Weather-Ometer 63 8.3 9 Data from GE Plastics literature 99 0.35 Watts/sq-m irradiance 340 nm tensile strength at yield Specimen Without stabilizer 

Acetic Acid 5 60 9 Resistant little or no change in weight small effect on mechanical properties generally suitable for practical use PSU 1000 Quadrant EPP 

Woishnis and Ebnesajjad. Chemical Resistance of Specialty Thermoplastics. DOI http //dx.doi.org/10.1016/B978-l-4557-3110-7.00014 2 

Resistance note % Change % Retained Test note Material note 

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The isopropylidene linkage imparts chemical resistance, the ether linkage imparts temperature resistance, and the sulfone linkage imparts impact strength. The brittleness temperature of polysulfones is — 100°C. Polysulfones are clear, strong, nontoxic, and virtually unbreakable. They do not hydrolyze during autoclaving and are resistant to acids, bases, aqueous solutions, aliphatic hydrocarbons, and alcohols. 

Styrene-acrylonitrile copolymer Styrene- butadiene copolymer, high-impact Polysulfone ... 

Polysulfide sealants Polysulfide units Polysulfonates Polysulfone... 

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