Rubbers improved in thermal stability and resistance to microorganisms

Bis(4-hydroxyphenyl)sulfoxide and brominated bisphenols A, viz., tetrabromobis(4-hydroxyphenyl)propane and tetrabromobis(4-hydroxyphenyl)sulfoxide, were synthesized and used to modify natural rubber, styrene-butadiene rubber, and nitrile-butadiene rubber. Chloroprene rubber, carbon black and clay were used as fillers. The ingredients (Table 2) were mixed in a two-roller mill at 150 degrees C for 15 min. Cured films were prepared and selected mechanical and thermal properties as well as resistance to mineral oils and to microorganisms were examined. Tetrabromobis(4-hydroxyphenyl)sulfoxide and chloroprene rubber imparted enhanced mechanical and thermal insulation properties and also a significant resistance to microorganisms.