Polysulfone Foams

Polysulfone Foams Polysulfone resins were introduced by Union Carbide Corporation in 1965 to produce stable and self-extinguishing thermoplastics. The polysulfones contain the sulfur atom in its highest excitation state, and hence are resistant to oxidation. The structure is as follows  

Up to 1973 very little information had been published on these foams. France has produced polysulfone foams from expandable beads which resemble polystyrene beads in their processing. In a typical formulation 1- butene and sulfur dioxide are copolymerized in such a way that the copolymer contains excess unpolymerized 1-butene, which volatilizes to cause foaming. Water, ethyl hydroxyethyl cellulose, 1-butene, sulfur dioxide, and a solution of isoprophyl peroxydicaibonate in 

Molded articles from cellular polysulfone, coated with polystyrene, epoxy resin, or vinyl resin, are reported to have improved hardness and surface rigidity. They can also be used as insulating or packaging materials, or, when modified with urea-formaldehyde resin, as flowerpots that are permeable to air and water. These foams have excellent selfextinguishing and low anoke-generating properties (21). 

Whittington, L.R., Whittington s Dictionary of Plastics, 2nd Edition, Sponsored by the Society of Plastics Engineers, Techno-mic, Westport, Connecticut (1978). 

edition 2, Desk-Top Data Bard, edited by M.J. Howard, The International Plastics Selector, Inc., San Diego, California (1980). 

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Discussions on cross-linked vinyl foams, which are rigid, can be found below under Vinyl Foams, and rigid cellular cellulose acetate (CCA) foams and polysulfone foams are discussed in the section under Miscellaneous Foams. 

Sun, H. and J. E. Mark. 2002. Preparation, characterization, and mechanical properties of some microcellular polysulfone foams. Journal of Applied Polymer Science 86 (7) (November 14) 1692-1701. doi 10.1002/app.ll070. http //doi.wiley.eom/10.1002/app.11070. 

The coal-water mixture fed to the boilers has to be formulated to a certain specification. This is done with the proper inclusion of additives to facilitate combustion. The recommended additives include a petroleum-based surfactant (polysulfones or polycar-boxylates), a stabilizing (e.g. xanthan gum), a biocide and an anti-foaming agent (such as a silicone base). 

As of 1992, the first specialty platable plastic, acrylonitrile—butadiene—styrene (ABS) terpolymer (see Acrylonitrile polymers, abs resins), is used in over 90% of POP applications. Other platable plastics include poly(phenylene ether) (see Polyethers), nylon (see Polyamides), polysulfone (see Polymers containing sulfur), polypropylene, polycarbonate, phenolics (see Pphenolic resins), polycarbonate—ABS alloys, polyesters (qv), foamed polystyrene (see Styrene plastics), and other foamed plastics (qv). 

Burning may be considered another means of oxidation. Non-burning plastics are a must in commercial constructions according to building codes and are often required for automotive, electronic, and electrical applications. From the numerous thermoplastics, only the halogen-containing polymers, polyamides, polycarbonate, poly(phenylene oxide), polysulfone, and polyimides are self-extinguishing. Even these, such as poly (vinyl chloride), may become flammable when plasticized with a flammable plasticizer. Fire control can be the key to volume use of plastics. Polyester panels, urethane foam, and PVC tarpaulins account for nearly 90% of all fire retardants consumed. Consumption in 1967... 

Polysulfones which are produced at an annual rate of 20 thousand tons are being used for ignition components, hair driers, cookware and structural foams. (ZZ)... 

FIGURE 20,5-1 Demonstration of typical permeability creep behavior observed for asymmetric membranes. Both cellulose acetate and polysulfone display this behavior, which is believed to be related to densification of the dense separating layer or compaction of the support foam structure shown in Fig. 20.1-6. ... 

The good heat resistance and electrical properties of polysulfones allows them to he used in applications such as circuit boards and TV components. Chemical and heat resistance are important properties for automotive apphcations. Hair dryer components can also be made from polysulfones. Polysulfones find application in ignition components and structural foams. Another important market for polysulfones is microwave cook-... 

Addition of a small amount of PSF to a variety of resins improves hardness, the notched Izod impact strength, plateabflity, hydrolytic stability, and shape retention at high temperatures. Many PSF blends of or with engineering resins have been developed, viz., with PA, PEST, PC, PPE, or POM. They have high HDT, heat resistance, strength, stiffness, mechanical properties, and ESCR. Polysulfone blends have been foamed using water and either N2 or CO2 (Bland and Conte... 

Structural foam molding ABS, acetal, nylon, polycarbonate, polyethylene, polyphenylene oxide, polypropylene, polystyrene, polysulfone, SAN... 

Several plastics can be plated on a commercial scale as shown in Table M.l. Some thermoplastics that can be readily etched and plated include ABS, modified PPO, modihed polypropylene, and polysulfone. Some grades of foamed plastics can also be plated. The greatest volume of plated plastic is represented by ABS and modihed PPO. 

Polystyrene foam has been extensively sulfonated by treatment with one or more of the following reagents oleum, chlorosulfonic acid, fluorosulfonic acid or sulfur trioxide. The polysulfonated polystyrenes were useful as shock absorbers in packaging and formed conductive, antistatic, condensation-inhibiting, fire-resistant coatings. - ... 

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