Transparent engineering thermoplastics

Udel is a slightly yellow but transparent engineering thermoplastic. It has low flammability and smoke emission and good electrical properties. It has excellent resistance to water, steam, and alkaline solutions. Specific uses for Udel include microwave cookware, beverage dispensers, coffee brewers, cookware, hair dryers, com poppers, and steam table trays. Its steam resistance makes it particularly fit for a dishwasher environment. Properties of polysulfone resins are given in Table 11. 

Polysulfones constitute a family of high-performance transparent engineering thermoplastics with high oxidative and hydrolytic stability and excellent high-temperature properties. They may be prepared by condensation polymerization of 4,4 -dichlorophenyl sulfone with aUcah salt of bisphenol A in polar solvents like dimethylsulfoxide (DMF) or sulfolane. 

Definition Transparent engineering thermoplastic with good creep resist., thermal/elec. props. selfextinguishing resist, to attack by aq. acid, alkali, most soivs. 

Table 5.90 Comparative chemical resistance of transparent engineering thermoplastics...

Color/Transparency. Almost all amorphous engineering thermoplastics, except PC and some polyester carbonates, are inherently colored. Even polycarbonates have yellowness indexes (YI) (36) of 0.1 to 5.0. Colorless material is produced from these resins by compounding with complementary blue dyes which reduce transmission. Ha2e in amorphous resins is an indication of particulates. Ha2e reduces optical clarity and transmission. 

By using mixtures of adipic and azelaic acids as monomers in the reaction with MDI, transparent copolymers are obtained useful as engineering thermoplastics. Also, copolyamides obtained from mixtures of isophthalic (IPA) and azelaic acids and MDI/TDI mixtures have been made. TDI in combination with MDI is used to lower the melt temperature of the IPA/MDI blocks to allow thermoplastic processing. 

Diphenyl carbonate (DPC) is a carbonate ester of formula (QH50)2C0. The principal use of DPC is as a critical comonomer in the manufacture of polycarbonate resin, an engineering thermoplastic with high impact resistance and excellent optical properties. It is widely used as a heat-resistant and flame-retardant insulator in electronics, a construction material, and an optical material for data storage (CD and DVD disks) and in manufacturing transparent parts in automotive and aerospace industries [1]. 

Commercial polyetherimide (PEI Ultem , Sabic) is a transparent, amorphous, high-performance engineering thermoplastic with its repeat unit structure containing both the rigid aromatic imide units and the slightly more flexible... 

Polycarbonate (PC) is the fourth largest volume material. It is an amorphous engineering thermoplastic with good thermal stability, transparency, impact resistance and the ability to be processed on conventional machinery. Its surface properties are important for many applications, including medical, optics and so on. Table 2.10 illustrates the properties of PC. 

Transparent (clear) engineering thermoplastics are used increasingly for medical, automotive, and architectural products windows, skylights, panels compact disks, fiber-optics sleeves lenses, reflectors, and light transmission pipes. ASTM D1003 (ISO 14782/13468), Haze and Luminous Transmittance of Transparent Plastics (Hazemeter or Spectrometer), describes optical properties of thermoplastics. 

MBS impact modifiers are used for PVC (transparent and low temperature applications, mainly in packaging), and for engineering thermoplastics, especially for low temperature applications (PC, PBT and blends). 

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