An isoprene-butadiene copolymer rubber having improved processing properties which comprises a microstructure of the butadiene portion having from 70% to 90% of trans-1,4 linkage and from 2% to 8% of vinyl linkage, an isoprene content of from 3 to 25 wt %, and a styrene content of from 0 to 30 wt %, said copolymer rubber having a Mooney Viscosity of from 30 to
G. Akovali, in Toxicity of Building Materials, 2012 3.2.3 CR (CAS number: 9010-98-4). CR (chloroprene rubber, polychloroprene, poly[2-chloro-1,3 butadiene], also known by the generic names of first 'DuPrene' and later 'neoprene', is composed of mostly trans-1.4-polychloroprene with the formula [CH 2 –CCl = CH–CH 2] n.It is an important diene-based elastomer produced