Characterization of the Aging Behavior of Microorganism Coagulated Natural Rubber
The characterization of the aging behavior of raw natural rubber (NR) coagulated by microorganisms (NR-m) was performed on a rubber processing analyzer (RPA) by tests of frequency sweep, strain sweep and stress relaxation, respectively. With the prolongation of the aging time, the storage modulus (G'), storage torque (S'), complex viscosity (η*) and stress relaxation time of raw NR-m decreased while the damping factor (tanδ) were increased. As the oscillation frequency was increasing, the G' rose gradually but the tanδ decreased. The η* diminished over the whole range of frequency shear rate (γƒ) values. Its change remained all almost the same at low strain shear rate (γs) but began to decrease sharply when the rate reached a higher value. The S' soared up in the region of less than 10°, but began to slow down after that point.
Jinglong Bu, Pengcheng Wang, Liqun Ai, Xiaoming Sang, Yungang Li
W. J. Luo et al., "Characterization of the Aging Behavior of Microorganism Coagulated Natural Rubber", Advanced Materials Research, Vols. 287-290, pp. 1517-1520, 2011