Structure of the interfacial layer and properties of crosslinked heterophase blends based on butadiene-nitrile and ethylene-propylene-diene elastomers

Structure of the interfacial layer in blends of elastomers with different polarities and ozone resistance

“…Formation of a strong interfacial layer is the key factor of the mechanism describing retardation of ozone degradation of a diene rubber by elastomer additives with a low degree of unsaturation [1][2][3]. The effect of comonomer ratio in ethylene-propylene-diene terpolymers (EPDMs) and stereoregularity of propylene units on the interfacial interaction and the amount of crosslinks in the interfacial layer was considered for heterophase crosslinked blends with butadiene-acrylonitrile rubbers (BNRs) of different polarities.…”

“…Data on the efficiency of retardation of the ozone induced degradation of diene rubber in the absence (85:15 blend) and presence of the EPDM network (70:30 blend) at different strains are given in Table 3. In the case of the continuous EPDM network, the degradation rate for the BNKS-18 or BKNS-28 matrix reaches a minimum (value v d rel is maximum) [2,3]. The efficiency of retardation of the ozone degradation of BNKS-18 in the presence of the Royalen EPDMs (except R 505), which have a high stereoregularity of propylene units, is much higher than that in the case of DSM EPDMs of the same composition In blends of highly polar NBRs, v d rel sharply decreases and the differences between the blends level out.…”