Resistance high-temperature

Cycloaliphatic amines can also provide high heat resistance when cured with a liquid DGEB A epoxy at room temperature (although better high-temperature characteristics can be achieved with an elevated-temperature cure). A range of cure schedules and working 

TABLE 11.22 High-Temperature Epoxy Adhesive That Cures at Room Temperature31 

Tensile shear strength, psi, on aluminum when tested at -55°C 1900 

TABLE 11.23 H2S04 Acid Resistance of Epoxy Adhesive Formulations Cured 1 Week at 25°C32 

Petroleum extender Coal tar extender Accelerated aromatic amine (e.g., Epi-Cure 8494) 73 81 45 

---

Acrylonitrile has contributed the desirable properties of rigidity, high temperature resistance, clarity, solvent resistance, and gas impermeabiUty to many polymeric systems. Its availabiUty, reactivity, and low cost ensure a continuing market presence and provide potential for many new appHcations. 

High temperature resistance of ETEE and other fluoropolymers ia automotive fuels and their permeation resistance have been discussed (28,29). 

Polyester. Poly(ethylene terephthalate) [25038-59-9] (PET) polyester film has intermediate gas- and water- vapor barrier properties, very high tensile and impact strengths, and high temperature resistance (see Polyesters, thermoplastic). AppHcations include use as an outer web in laminations to protect aluminum foil. It is coated with PVDC to function as the flat or sealing web for vacuum/gas flush packaged processed meat, cheese, or fresh pasta. 

Polyquinolines are some of the most versatile thermally stable polymers they were developed during the 1970s in response to increasing demand for high temperature resistant materials and are undergoing commercial development (Maxdem, Inc., San Dimas, California). Evidence of their stabiUty is... 

Alkanoyl esters of phloroglucinol, eg, phloroglucinol trisheptanoate, are high temperature-resistant lubricants and high performance fluids (194). An aqueous solution of phloroglucinol (or of several of its simple derivatives) is used as a corrosion-resistant coating on galvanized sheet (195). The alkaU or... 

Thermal Properties. The inherent thermal stabiUty of PPS translates into high temperature resistance for short- as well as long-term exposure and retention of properties at elevated temperature. 

Considerable interest in the sohd-state physics of sihcon carbide, that is, the relation between its semiconductor characteristics and crystal growth, has resulted from the expectation that SiC would be useflil as a high temperature-resistant semiconductor in devices such as point-contact diodes (148), rectifiers (149), and transistors (150,151) for use at temperatures above those where sihcon or germanium metals fail (see Semiconductors). 

Thermosetting unsaturated polyester resins constitute the most common fiber-reinforced composite matrix today. According to the Committee on Resin Statistics of the Society of Plastics Industry (SPl), 454,000 t of unsaturated polyester were used in fiber-reinforced plastics in 1990. These materials are popular because of thek low price, ease of use, and excellent mechanical and chemical resistance properties. Over 227 t of phenoHc resins were used in fiber-reinforced plastics in 1990 (1 3). PhenoHc resins (qv) are used when thek inherent flame retardance, high temperature resistance, or low cost overcome the problems of processing difficulties and lower mechanical properties. 

Properties. Polyurethane elastomers generally exhibit good resiHence and low temperature properties, excellent abrasion resistance, moderate solvent resistance, and poor hydrolytic stabiHty and poor high temperature resistance. As castable mbber, polyurethanes enjoy a variety of uses, eg, footwear, toys, soHd tires, and foam mbber. 

Although these resins have been on the market for a number of years, volumes and appHcations remain low in spite of favorable properties including high temperature resistance, excellent wear and friction properties, good electrical properties, chemical inertness, and inherent nonflammability. ProcessibiHty and price may be the limiting factors. 

In the 1960s, CIBA Products Co. marketed and manufactured glycidylated o-cresol novolak resins, which had been developed by Koppers Co. as high temperature-resistant polymers. Dow offered glycidylated phenol novolak resins, SheU introduced polyglycidyl ethers of tetrafunctional phenols, and Union Carbide developed a triglycidyl p- am in oph en o1 resin. 

FRAZER, A. H., High Temperature Resistant Polymers, Interscience, New York (1968)... 

During World War II, several new synthetic elastomers were produced and new types of adhesives (mainly styrene-butadiene and acrylonitrile copolymers) were manufactured to produce adequate performance in joints produced with new difficult-to-bond substrates. Furthermore, formulations to work under extreme environmental conditions (high temperature, resistance to chemicals, improved resistance to ageing) were obtained using polychloroprene (Neoprene) adhesives. Most of those adhesives need vulcanization to perform properly. 

Neoprene XD. Developed in the 1980s, this polychloroprene family was prepared using special xanthogendisulphides as chain modifiers, offering improved processability and vulcanizate properties. In solution, these polychloroprenes show slow crystallization and high temperature resistance. 

High temperature resistance. If cured, NBR can easily perform at 150-175 C. 

Silicones. Silicones are useful where high temperature resistance or compatibility with silicone components such as molded seals are needed. Silicone firewall insulation materials and silicone gaskets and seals are bonded with silicone rubber adhesives. 

E.P.D.M. Paratherm 150 300 High temperature resistance for a wide range of chemicals... 

King, J. F., Adamson, K. G. and Unsworth, W., Impregnation of Anodic Films for the Protection of Magnesium Alloys, Ministry of Defence D.Mat. Report No. 193, February (1973) Adamson, K. G., King, J. F. and Unsworth, W., Evaluation of High Temperature Resistant Coatings for the Protection of Magnesium Alloys, Ministry of Detence D.Mat. Report No. 196, July (1973)... 

Table 4 shows the approved and standardized priming mixts which possess greater sensitivity than FA70, FA90, or FA956, previously listed (Refs 8,12,13,17 20) High-Temperature-Resistant Percussion Primers... 

---