3. Results and discussion
3.1. The cure characteristics and crosslink density
The cure characteristics of CB-filled SMR-L compounds, with
and without the presence of ALK at various curing systems, are
shown in Figs. 2 and 3 and Table 2. The addition of 5.0 phr of ALK
into the CB-filled SMR-L compound for each curing system caused a
decrease in scorch and cure times and an increase of torque difference.
Since amine is an ingredient of accelerators and also an
accelerator activator [12], the amine part of ALK, together with ZnO
and fatty acid, activated the MBTS-accelerator more pronouncedly
and, consequently, improved the rate of sulphur reaction of CBfilled
SMR-L compounds. The increase of torque difference value
was attributed to the additional function of ALK, as an internal