For this, XNBR and NR blends with various compositions have been examined for testing the wear resistance properties.
The optimum cure time for MC-2 and MC-3 rubber is lesser than PC-1 PC-2, OC-1 and OC-2 due to the mixing of XNBR with NR and is shown in Table 3.
The tensile strength of MC-1 is much higher than MC-2 and MC-3 due to the addition of more NR with XNBR.
This can be explained because PC-2 and OC-2 rubber contains certain amount silica, whereas MC-2 and MC-3 contain lesser amount of XNBR, which causes main chain degradation and lowers the percentage of elongation and hence tensile strength.
XNBR was compounded on a two-roil mill with 2 phr of DOP.
XNBR sheets were weighed and swollen in an excess amount of alkyl methacrylate containing 0.
The percent increase in weight of XNBR sheets, when swollen for 1 h in TEGDM, BuMA, EMA and MMA, were 26, 92, 129 and 192% respectively, which shows that the components actually swell the rubber prior to the IPN formation.
The dynamic mechanical properties of XNBR and some of the representative IPNs are illustrated in Figs.
In these cases, the properties of HNBR remain substantially unchanged, whereas those of FKM, NBR and XNBR suffer significant reduction in tensile strength.
In the described tests, Therban elastomer was compared with FKM, NBR and XNBR, all of which are known to withstand heat and/or oil swells.
For example, it is generally recognized that XNBR, due to its carboxyl functionality, exhibits higher water swell than NBR.
HXNBR was compared directly to a XNBR
in a typical paper making roll formulation (ref.