Evaluation of the properties of some nitrile-butadiene rubber/polychloroprene mixes and vulcanizates

Nitrile-butadiene rubber (NBR) has been blended with polychloroprene (CX) i n a weight ratio of I:I. The vulcanizing systems in the blend formulations were varied to obtain non crosslinked CR embedded in vulcanized NBR and non crosslinked NBR embedded in vulcanized CX. The effects of these two differ ent phases on the rheological and mechanical characteristics were evaluated . In addition, the dynamic compliance of the blends was measured over wide ranges of frequency and temperature. It has been found that the mechanical and rheological properties oft he vulcanized blends depend on the type of v ulcanizing system, its concentration and the presence of reinforcing filler , The mechanical properties of the blend containing N-cyclohexyl-2-benzthin zyl sulphenamide/S as vulcanizing system suitable for NBR are higher than t hose of the blend containing non-sulfur vulcanizing system? (Zno/Mgo and et hylene thiourea) suitable for CX. Both types of rubber (CX and NBR) in the blend are incompatible as two glass transition temperatures have been obser ved. Copyright (C) 2000 John Wiley & Sons, Ltd.