Neoprene heat resistant compounds

Elastomers used for connector insulators include polychloroprenes, silicones, fluoro-silicones and heat-setting compounds which enable the special characteristics to be incorporated for example, flame resistance, low toxicity and low smoke. Neoprene is used as spacer material and also for washers where its sealing qualities, good resistance to cracking, rotting, oils and petrol and its good low temperamre flexibility may be beneficial in specific applications. 

Acceleration by ethylene thiourea is more effective with W- and WRT- based compounds than the G types. The neoprene G type compound is cheaper and inferior in abrasion, heat resistance and low temperature properties. 

Adhesives based on Neoprene AF, a reactive copolymer of chloroprene and methacrylic acid, are characterized by faster bond strength development (Fig. 1), increased heat resistance, and better resistance to phasing than the fast-crystallizing types. However, because of its reactivity, the use of Neoprene AF requires special attention to processing, compounding, and raw polymer inventory control. If it is substituted directly into a formulation based on Neoprene AC or AD, the results may be disappointing. 

HEAT RESISTANT NEOPRENE COMPOUNDS TO MEET DTD 5514 SPECIFICATION... 

The rotary seal compound is sticky during mixing, but the O ring compound is not. The activator RCD 2098 is a zinc chloride/MBTS complex. Zinc diethyl dithiocarbamate and other activators containing zinc may also be used, but they are less effective. These polyurethanes have outstanding abrasion resistance, similar to neoprene in ozone and weather resistance, and comparable to nitrile rubbers in oil and fuel resistance. Heat aging is excellent up to 250°F (121°C), and the brittle point is —90°F (—68°C). 

Neoprene provides a versatile elastomeric base in the formulation of solvent based adhesives. Properly compounded adhesives are resistant to degradation from exposure to heat, sunlight, ozone, water, oils, and chemicals. Neoprene can be dissolved in many solvent blends to give adhesive solutions which are stable for extended periods of time. Solvent selection, therefore, allows a great deal of variation in adhesive viscosity and drying rate. Other com-... 

Because these compounds are easily colored, they can be made with heat reflective or absorptive colors as required. An alternative approach to weather resistant roofing is to coat a neoprene or EPDM base with CM paint. 

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