Temperatures were
controlled within ±0.5 ◦C of the set values and monitored by platinum
resistance thermometers fitted in the three (top, middle and
bottom) zones of the barrel. The polymer was fed into both bores
of the barrel and manually compressed before the test was started.
The polymerwas subjected to pre-compression pressure of 0.5MPa,
and a total pre-heating time of 240 s. The instrument was run in
8-stage discrete speed programme. The piston speedwas automatically
converted to shear rate by software and is summarised in
Table 1.