High temperature plastics polymers, resins

During the 1980s and 1990s, the pace of research and commercialisation of high-temperature plastics accelerated dramatically. The thermoplastic resin manufacturers introduced many new materials based on imide, sulfone, and ketone-based polymers. These include polyetherimide (1982) and polyphthalamide (1991). Polyketones and liquid crystal polymers were also commercialised in the 1990s. 

Ethyl Vinyl Ether. The addition of ethanol to acetylene gives ethyl vinyl ether [104-92-2] (351—355). The vapor-phase reaction is generally mn at 1.38—2.07 MPa (13.6—20.4 atm) and temperatures of 160—180°C with alkaline catalysts such as potassium hydroxide and potassium ethoxide. High molecular weight polymers of ethyl vinyl ether are used for pressure-sensitive adhesives, viscosity-index improvers, coatings and films lower molecular weight polymers are plasticizers and resin modifiers. 

As shown in Table 15.5, the epoxy plastics have fair resistance to high temperatures and have good mechanical properties. Cured epoxy resins are resistant to nonoxidizing acids, alkalis, and salts. Because of the presence of polar hydroxyl pendant groups, these polymers have good adhesion to substrates such as wood or metal. 

Stabilizers, plasticizers, and lubricants do not have to be added for processing since high temperatures are not required to dry the film. In addition, any polymer soluble in the solvent (THF, etc.) that will not adhere to the stainless steel belt can be alloyed with PVC or cast by itself. Typical examples include butadiene rubber, acrylic, EVA, and saran. Special PVC resins provide wide and low heat sealing ranges in rigid films. For example, an unplasticized film can be cast with a heat... 

Plastics in general (including all forms) are sensitive to high temperatures, among the more resistant being fluorocarbon resins, nylon, phenolics, polyim-ides, and silicones, though even these soften or melt above 260C. Other types (cellulosics, polyethylene, acrylic polymers, polystyrene) are combustible when exposed to flame for a short time and still others (polyurethane) burn with evolution of toxic fumes. 

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