Polyphenylene oxide properties

Polyphenylene oxide)s. Properties Comparison Chart, General Electric Co., Pittsfield, Mass., 1969. 

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. 

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. 

The effect of blending LDPE with EVA or a styrene-isoprene block copolymer was investigated (178). The properties (thermal expansion coefficient. Young s modulus, thermal conductivity) of the foamed blends usually lie between the limits of the foamed constituents, although the relationship between property and blend content is not always linear. The reasons must he in the microstructure most polymer pairs are immiscible, but some such as PS/polyphenylene oxide (PPO) are miscible. Eor the immiscible blends, the majority phase tends to be continuous, but the form of the minor phase can vary. Blends of EVA and metallocene catalysed ethylene-octene copolymer have different morphologies depending on the EVA content (5). With 25% EVA, the EVA phase appears as fine spherical inclusions in the LDPE matrix. The results of these experiments on polymer films will apply to foams made from the same polymers. 

A comparative stndy is made of the properties of energy absorbing foams nsed in passenger protection in cars, with particular reference to dynamic impact and compression strength. Materials examined inclnde polyurethanes, PP, PS and polyphenylene oxide/PS. 7 refs. 

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. 

Table 15.9 Thermal and Physical Properties of Polyphenylene Oxide (Typical...

Polyphenylene oxide (PPO) or Polyphenylene ether (PPE) is an amorphous polymer with a softening temperature of about 210 °C. To improve its processability it is mostly blended with PS (modified PPE, e.g. Noryl ), which is at the cost of its heat distortion temperature. The properties are excellent the applications are mainly in fine-mechanical construction, in automotive parts, in household equipment etc. 

Comparison of Permeability and Separation Properties of the CsHe/CsHs System for Individual Penetrants, as well as for Their Equimolar Mixture, in Various Polyimides and in Polyphenylene Oxide PPO... 

The initial microporous support films used in the work were made from cellulose acetate by a modification of the Loeb-Sourirajan procedure. Later work showed that several types of the membrane filters manufactured by Millipore Corporation and Gelman Sciences, Inc., performed as well and allowed higher flux. A continued search for a more compression-resistant support film led to the development of polycarbonate, polyphenylene oxide and polysulfone microporous films in 1966 to 1967 (8). Of these, microporous polysulfone film proved to have the best properties. The polysulfone support was made by casting a liquid layer of a 12.5 to 15 percent solution of Union Carbide Udel P35OO polysulfone in dimethylformamide onto a glass plate at 4 to 7 mils (100-175 pm) thickness, then coagulating the film in water. 

An important requirement for plastics materials in the automotive industry is paintability alongside metal components in high temperature areas. Noryl GTX series of General Electric has been developed to meet this requirement. The blend consisting of polyphenylene oxide (PPO) in a nylon matrix combines the heat and dimensional stability and the low water absorption of PPO with the flow and semicrystalline properties of nylons. Its impact strength, however, is not as high as PC/PBT blends. 

H.-J. Lee, D.-P. Kim, H. Suda, and K. Haraya. Gas permeation properties for the post-oxidized polyphenylene oxide (PPG) derived carbon membranes Effect of the oxidation temperature. / Membr. ScL, 282(l-2) 82-88, October 2006. 

Polyphenylenes The polyphenylene-based thermoplastics family includes polyphenylene ether (PPE), polyphenylene oxide (PPO), and polyphenylene sulphide (PPS). They have been one of the most successful groups introduced in the medium/higher range of cost/performance, with good heat stability and particularly good flammability properties. 

PROPERTIES OF POLYPHENYLENE OXIDE IN REGARD TO ITS APPLICATION IN LIQUID HYDROGEN TANK INSULATION. KNOBBOUT J A COLENBRANDER C B CENTRAL... 

Lee HJ, Suda H, Haraya K, Moon SH. Gas permeation properties of carbon molecular sieving membranes derived from the polymer blend of polyphenylene oxide (PPO)/polyvin-ylpyrrolidone (PVP). J Membr Sci 2007 296(1-2) 139-46. 

Another complication is that thin dense membrane films have been shown to decline in permeation properties over extended periods of time (10000hours) even without external stresses. The rate of ageing effect becomes greater the thinner the film [37]. This loss over extended time is presumably due to cast membrane films slowly reorienting polymer chains to achieve equilibrium properties with reduced free volume. The thin dense films used in these studies (0.4-25 pm) approach the same order of thickness as the active layer of cast asymmetric films at less than 2000 A (0.2 pm). The property appears common in that it was reported in this paper with polysulfone, polyphenylene oxide and polyimide... 

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