Polyphenylene oxide plastic

In 1966, Cadotte developed a method for casting mlcroporous support film from polysulfone, polycarbonate, and polyphenylene oxide plastics ( ). Of these, polysulfone (Union Carbide Corporation, Udel P-3500) proved to have the best combination of compaction resistance and surface microporosity. Use of the mlcroporous sheet as a support for ultrathin cellulose acetate membranes produced fluxes of 10 to 15 gfd, an increase of about five-fold over that of the original mlcroporous asymmetric cellulose acetate support. Since that time, mlcroporous polysulfone has been widely adopted as the material of choice for the support film in composite membranes, while finding use itself in many ultrafiltration processes. 

Noryl GE Plastics tradename for its family of polyphenylene oxide plastics. 

Polypropylene has a chemical resistance about the same as that of polyethylene, but it can be used at 120°C (250°F). Polycarbonate is a relatively high-temperature plastic. It can be used up to 150°C (300°F). Resistance to mineral acids is good. Strong alkalies slowly decompose it, but mild alkalies do not. It is partially soluble in aromatic solvents and soluble in chlorinated hydrocarbons. Polyphenylene oxide has good resistance to ahphatic solvents, acids, and bases but poor resistance to esters, ketones, and aromatic or chlorinated solvents. 

Certain polymers have come to be considered standard building blocks of the polyblends. For example, impact strength may be improved by using polycarbonate, ABS and polyurethanes. Heat resistance is improved by using polyphenylene oxide, polysulphone, PVC, polyester (PET and PBT) and acrylic. Barrier properties are improved by using plastics such as ethylene vinyl alchol (EVA). Some modem plastic alloys and their main characteristics are given in Table 1.2. 

Odor and taste Polystyrene, styrene-acrylonitrile, polyethylene, acrylic, ABS, polysulfone, EVA, polyphenylene oxide, and many other TPs are examples of satisfactorily odor-free. FDA approvals are available for many of these plastics. Food packaging and refrigerating conditions will also eliminate certain plastics. There are TPs and melamine as well as urea compounds that are suitable for this service. 

Between 250 and 450°F (121 and 232°C), plastics used include glass or mineral-filled phenolics, melamines, alkyds, silicones, nylons, polyphenylene oxides, polysulfones, polycarbonates, methylpentenes, fluorocarbons, polypropylenes, and diallyl phthalates. The addition of glass fillers to the thermoplastics can raise the useful temperature range as much as 100°F and at the same time shortens the molding cycle. 

Flame resistance The underwriters ruling on the use of self-extinguishing plastics for contact-carrying members and many other components introduces critical material selection problems. All TSs are basically self-extinguishing. Nylon, polyphenylene oxide, polysulfone, polycarbonate, vinyl, chlorinated polyether, chlorotrifluoroethy-lene, vinylidene fluoride, and fluorocarbon are examples of TPs that may be suitable for applications requiring self-extinguishing properties. Cellulose acetate and ABS are also available with these properties. Glass reinforcement improves these materials considerably. 

Moisture Deteriorating effects of moisture are well known as reviewed early in this chapter (OTHER BEHAVIOR, Drying Plastic). Examples for high moisture applications include polyphenylene oxide, polysulfone, acrylic, butyrate, diallyl phthalate, glass-bonded mica, mineral-filled phenolic, chlorotrifluoroethylene, vinylidene, chlorinated polyether chloride, vinylidene fluoride, and fluorocarbon. Diallyl phthalate, polysulfone, and polyphenylene oxide have performed well with moisture/steam on one side and air on the other (a troublesome... 

Dimensional stability There is plastics with very good dimensional stability, and they are suitable where some age and environmental dimensional changes are permissible. These materials include polyphenylene oxide, polysulfone, phenoxy, mineral-filled phenolic, diallyl phthalate, epoxy, rigid vinyl, styrene, and various RPs. Such products will gain from an after-bake for dimensional stabilization. Glass fillers will improve the dimensional stability of all plastics. 

Polyphenylene oxide modified Very fough engineering plastic, superior dimensional stability, low moisture absorption, excellent chemical resistance Injection molding... 

Many of the commercially important plastics such as polystyrene, polyamide, polyester, polycarbonate, polysulfone, polyphenylene oxide alloys, epoxy, and phenolics lack good impact... 

Several flexible polymers, such as natural rubber (NR) synthetic rubber (SR) polyalkyl acrylates copolymers of acrylonitrile, butadiene, and styrene, (ABS) and polyvinyl alkyl ethers, have been used to improve the impact resistance of PS and PVC. PS and copolymers of ethylene and propylene have been used to increase the ductility of polyphenylene oxide (PPO) and nylon 66, respectively. The mechanical properties of several other engineering plastics have been improved by blending them with thermoplastics. 

Engineering plastics are most frequently thought of as the acetals, nylons, fluorocarbons, phenolics, polycarbonate, and polyphenylene oxide, to name just a few. These are indeed engineering materials and for such applications are usually used in relatively small... 

Mixed esters, such as isopropylphenyl diphenyl phosphate and tcrt-butylphenyl diphenyl phosphate, are also widely used as both plasticizers/flame retardants for engineering thermoplastics and hydraulic fluids.11 These esters generally show slightly less flame-retardant efficacy, when compared to triaryl counterparts however, they have the added advantage of lower smoke production when burned. Some novel oligomeric phosphate flame retardants (based on tetraphenyl resorcinol diphosphate) are also employed to flame retard polyphenylene oxide blends, thermoplastic polyesters, polyamides, vinyls, and polycarbonates. 

Polyphenylene oxide Methanol Solvent degrease. Plastic is soluble in xylene and may be primed with adhesive in xylene solvent... 

To the range of engineering plastics were added polyethylene and polybutylene tereph-thalates (PET and PBT), as well as General Electric s polyethers, the PPO (polyphenylene oxide) produced through polymerization of 2,6-xylenol and the Noryl plastic produced by blending PPO with polystyrene. Other special polymers, derived like the polycarbonates from bisphenol A, were added to this range polyarylates, polysul-fones, polyetherimides. 

Kambour et al. performed extensive studies on the mechanisms of plasticization [18-25]. The correlation observed between the critical strain to craze and the extent of the glass-transition temperature (Tg) depression speaks strongly in favor of a mechanism of easier chain motion and hence easier void formation. In various studies on polycarbonate [19,24], polyphenylene oxide [20], polysulfone [21], polystyrene [22], and polyetherimide [25], Kambour and coauthors showed that the absorption of solvent and accompanying reduction in the polymer s glass-transition temperature could be correlated with a propensity for stress cracking. The experiments, performed over a wide range of polymer-solvent systems, allowed Kambour to observe that the critical strain to craze or crack was least in those systems where the polymer and the solvent had similar solubility values. The Hildebrand solubility parameter S [26] is defined as... 

In 1982 the leader in structural plastics used for structural foams parts was modified polyphenylene oxide (NORYL ), accounting for almost three-quarters of all material usage. Polycarbonate held a strong second materials position, followed by ABS, with polystyrene next (5). 

Use Disinfectants, solvents, pharmaceuticals, insecticides and fungicides, plasticizers, rubber chemicals, additives to lubricants and gasolines, manufacture of polyphenylene oxide (2,6-isomer only), wetting agents, dyestuffs. 

As in case of mixed cresols, mixed xylenols have been used for manufacture of carbolic soaps, disinfectants, wire enamels, and fire-retardant plasticizers. However, 2,4-xylenol, 2,6-xylenol, and 3,5-xylenols have been used for organic chemical synthesis. 2,6-Xylenol is a precursor for an engineering plastic polyphenylene oxide also known as polyphenylene ether. 

Results of some of these short-term tests are shown in Table II. A comparison is given between PPS and five other plastics nylon (Zytel 101), polycarbonate (Lexan 141), polysulfone (Bakelite Polysulfone), polyphenylene oxide (Noryl), and polyetherimide (Ultem 2300). The data presented are based upon retention of tensile strength for all plastics except the Ultem 2300, which is based upon retention of flexural strength. Unsuccessful attempts were made to injection mold ASTM Type IV tensile bars out of the Ultem compound, but flexural strength bars could be made. Experience has shown that chemical resistance tests monitored by flexural strength retention are comparable to those monitored by retention of tensile strength. 

Fortunately, the deficiencies of both the classic thermosets and general purpose thermoplastics have been overcome by the commercialization of a series of engineering plastics including polyacetals, polyamides, polycarbonate, polyphenylene oxide, polyaryl esters, polyaryl sulfones, polyphenylene sulfide, polyether ether ketones and polylmides. Many improvements in performance and processing of these new polymers may be anticipated through copolymerization, blending and the use of reinforcements. 

Spin relaxation in dilute solution has been employed to characterize local chain motion in several polymers with aromatic backbone units. The two general types examined so far are polyphenylene oxides (1-2) and aromatic polycarbonates (3-5) and these two types are the most common high impact resistant engineering plastics. The polymer considered in this report is an aromatic polyformal (see Figure 1) where the aromatic unit is identical to that of one of the polycarbonates. This polymer has a similar dynamic mechanical spectrum to the impact resistant polycarbonates (6 ) and is therefore an interesting system for comparison of chain dynamics. 

Noryl . [GE Plastics GE Plastics Ltd.] Modified polyphenylene oxide resins engineering resin for inj. mcdding, ex> trasitm, structural foam used for computers, business equip., automotive, elec., electronics, construction, telecommunications, tqppliances, and other industries. 

ORIGIN/INDUSTRY SOURCES/USES from coal tar fractionation and coal processing intermediate in manufacturing of phenolic antioxidants pharmaceuticals plastics resins disinfectants solvents insecticides fungicides rubber chemicals polyphenylene oxide dyestuffs cresylic acid constituent wetting agent additive of lubricants and gasoline... 

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