Figure 3 shows the plot of log Mooney unit
from the stress relaxation test of NR for different forms.
Depending on the Hevea brasiliensis clones used, TSR5CV NR samples could have a [V.sub.R2] ranging from 39 to 87 uM (Mooney unit
The curing characteristics [t.sub.5] (time taken to achieve five Mooney unit
above the minimum viscosity), [t.sub.35] (time taken to achieve 35 Mooney units
above the minimum viscosity) and the cure index was calculated by using the following equation ;
In table 3, the time for a 30 Mooney unit
rise, t[Delta.sub.30], (sometimes referred to as the Mooney cure rate) is given along with the scorch delay [t.sub.5].
One Mooney unit
is equal to 0.083 N*m (0.735 lbf*in).
As seen in figure 2, when silica loading is increased from 80 phr to 100 phr, the viscosity of the compound significantly increases from 63 Mooney units
to 87 Mooney units
Key statement: The crosslinkable rubber composition comprises a first elastomer consisting of polybutadiene having a Mooney plasticity ranging from 40 to 70 Mooney units
, the content of the first elastomer being strictly greater than 50 phr, a second elastomer, and a carbon black having a specific surface area within a range of values extending from 15 m2/g to 25 m2/g and an oil adsorption number of compressed sample (COAN) within a range of values extending from 65 ml/100 g to 85 ml/100 g.
The Mooney viscosity of grade TSR 10 samples varied in the same manner to attain a limiting value after about 16 min, whereas those of the grade TSR 3CV samples decreased to give two distinct trends: the reduction was rapid and continuous throughout mastication for clone PB 217 samples, from an initial value of about 50 to less than 10 Mooney units
after prolonged mastication for 20 min.
Natural rubber SMR GP, from BR-THAI, Eastern GR Thailandia --Chonburi, Lee Rubber, with 65 Mooney Units
Mooney viscosity (ML) is reported as ML (1+4) at 125[degrees]C in Mooney units
, where L designates "large" rotor and the two numbers in parenthesis refer to the pre-heat time and test time according to ASTM D 1646-99.
* Synthetic poly( 1,4-c/s-isoprene) (IR) (Nizhnekamskneftechim Export) had the trade name SKI3 and 70 Mooney units
(MU) as Mooney viscosity ([M.sub.L] [1+4] 100[degrees]C).
Nitrile butadiene rubber (NBR) grades with acrylonitrile (ACN) content from 17% to 40% and viscosity from 35 to 120 Mooney units