Abstract:
Property variations with maturity time and storage conditions have been a
potential problem in compounding and processing of natural rubber (NR)
centrifuged latex. Concentrated NR latex needed to be stored for 21 days of
maturity period prior to processing in order to achieve acceptable level of
properties and this is a problem in production operations. The main
objective of this study was to investigate the property variations of natural
rubber centrifuged latex with different maturity time and with different
storage conditions (aerobic and anaerobic). During the experiment, changes
in properties of high ammonia (0.7% w/w) NR centrifuged latex were
evaluated at different maturity stages (0, 5, 10, 20, 30, 40, 50 and 60). The
samples were stored at room temperature (28±2
oC) and Volatile Fatty Acid
(VFA) Number, Mechanical Stability Time (MST) and Potassium
Hydroxide (KOH) Number were studied. Another two sets of samples were
kept under aerobic and anaerobic storage conditions for 21 days and
variation of the same properties were evaluated. Concentrated natural
rubber latex properties have changed significantly (p<0.05) with the
maturity time. There was a significant difference in MST and KOH number
with storage condition, while VFA number was not affected, significantly. It
is found that optimum latex properties could be achieved in less than 20
days by keeping under aerobic storage condition which was identified as a
great achievement with respect to the production operation process of NR
latex.