Engineering thermoplastics poly oxide

Alkylated phenol derivatives are used as raw materials for the production of resins, novolaks (alcohol-soluble resins of the phenol—formaldehyde type), herbicides, insecticides, antioxidants, and other chemicals. The synthesis of 2,6-xylenol [576-26-1] h.a.s become commercially important since PPO resin, poly(2,6-dimethyl phenylene oxide), an engineering thermoplastic, was developed (114,115). The demand for (9-cresol and 2,6-xylenol (2,6-dimethylphenol) increased further in the 1980s along with the growing use of epoxy cresol novolak (ECN) in the electronics industries and poly(phenylene ether) resin in the automobile industries. The ECN is derived from o-cresol, and poly(phenylene ether) resin is derived from 2,6-xylenol. 

PESA can be blended with various thermoplastics to alter or enhance their basic characteristics. Depending on the nature of thermoplastic, whether it is compatible with the polyamide block or with the soft ether or ester segments, the product is hard, nontacky or sticky, soft, and flexible. A small amount of PESA can be blended to engineering thermoplastics, e.g., polyethylene terepthalate (PET), polybutylene terepthalate (PBT), polypropylene oxide (PPO), polyphenylene sulfide (PPS), or poly-ether amide (PEI) for impact modification of the thermoplastic, whereas small amount of thermoplastic, e.g., nylon or PBT, can increase the hardness and flex modulus of PESA or PEE A [247]. 

Table 2 contains idealized structures of some CPs with typical dopants and values for the conductivities of thin films. The exact structures of PPy and poly thiophene (PT) are unknown. Polyacetylene is the most crystalline and PANi can exist in several oxidation states with electrical conductivities varying from 10 S/cm to the values reported in Table 2. In its undoped state, PPS is an engineering thermoplastic with a conductivity of less than 10 S/cm. Upon doping with ASF5, conductivities as high as 200S/cm have been obtained after casting a film from a solution of AsFsP ...

Poly(arylene sulfone)s and poly(arylene ketone)s are important engineering thermoplastics, and display high Tg-values, high thermal stabilities, good mechanical properties, and an exceptional resistance to both oxidation and acid-catalyzed hydrolysis. It is only during the past decade that the sulfonated aromatic polymers have been considered to be well-suited as PEM candidates for fuel cells [61-64]. 

The 1950s also saw the development of two families of plastics — acetal and polycarbonates. Together with nylon, phenoxy, polyimide, poly(phenylene oxide), and polysulfone they belong to the group of plastics known as the engineering thermoplastics. They have outstanding impact strength and thermal and dimensional stability — properties that place them in direct competition with more conventional materials like metals. 

Polyacetal polyphenylene oxide are widely used as engineering thermoplastics, and epoxy resins are used in adhesive and casting application. The main uses of poly(ethylene oxide) and poly(propylene oxide) are as macroglycols in the production of polyurethanes. Polysulfone is one of the high-temperature-resistant engineering plastics. 

Other engineering thermoplastics have also been examined and found to be effective e.g., polyetherimide [121-124], poly(ether ketones) (PEK) [125,126], poly(phenylene oxide) [127-129], and liquid crystalline polymers [130, 131]. 

In 1956, Allan S. Hay of the General Electric Company discovered a convenient catalytic oxidative route to poly(2,6-dimethylphenylene ether), or PPE. This amorphous polymer exhihited exceUent hydroljdic stability, an extremely high glass transition temperature [Tg = 419°F (215°C)], outstanding electrical properties over a wide temperature range, low density relative to other engineering thermoplastics, and a high melt viscosity. The polymer was introduced commercially in 1964 under the PPO trademark [1, 2]. 

High-performance engineering thermoplastics have recently assumed hicteas-ing importance due to their exceptional properties at elevated tenqioatures. A number of such spedalty polymers has been introduced into the market for higili-temperature applications and examples of some of the outstanding ones are poly phenylene oxide (PPO), poly fdienylene sulfide (PPS), polyetlier sulfone ES), polyaryl sulfone (PAS), polyether ether ketone (PEEIQ, polyetherimide (PEl, and polyarylate (PAr). 

Poly(arylene ether sulfones) (Fig. 11.9) are well-known engineering thermoplastics characterized by excellent thermal and mechanical properties, as well as resistance to oxidation and acid catalyzed hydrolysis [25],... 

Extruding a mixture of the oxidized olefin polymer material with an engineering thermoplastic, and optionally with additional virgin poly(olefin). 

Examples for engineering thermoplastic materials are poly(amide)s (PA)s, PCs, poly(imide)s, and poly(ester)s. The oxidation of the poly(olefin) can be achieved by the treatment with an organic peroxide initiator, such as tert-hutyl peroctoate (Lupersol PMS). 

The one engineering thermoplastic for which only limited blend activity has been reported involves poly(oxymethylene)(POM) (commercial since the 1960s). POM blends with phenoxy (PHE) were noted to be immiscible but exhibited good mechanical compatibility [523]. The miscibility of PHE with the next member of the poly(alkylene oxide) series (poly(ethylene oxide)) has been well noted. POM blends with the miscible PS/PPO blend showed decreasing crystallinity with a shift from bulk to homogeneous crystallization [524]. 

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