Papers by Author: Hong Hai Huang

Abstract: The properties of raw constant viscosity natural rubber were measured using a rubber processing analyzer. The results show that the rubber processing analyzer can characterize well the effect of viscosity stabilizer on the dynamic mechanical properties of raw constant viscosity rubber by applied strain sweep or frequency sweep. In linear viscoelastic region, the increment of the dynamic torque S’ of the constant viscosity natural rubber prepared with hydroxylamine hydrochloride decreases with the increase in the level of hydroxylamine hydrochloride . In the range of low frequency, the increment of the dynamic modulus G’ of constant viscosity natural rubber prepared with hydroxylamine hydrochloride is obvious lower than those of natural rubber and constant viscosity natural rubber prepared with aniline. G’ of the constant viscosity natural rubber prepared with aniline is just only a little higher than that of natural rubber. Hydroxylamine hydrochloride and aniline can decrease the molecular weight of rubber, and change the molecular weight distribution. The dynamical properties of constant viscosity natural rubber are dependent on the molecular weight and the molecular weight distribution.

Abstract: Effect of CMCS on the thermal stability of natural rubber(NR) was studied by means of TG-DTG,and the decomposition activation energy(Ea) was calculated through Flynn–Wall–Ozawa (FWO) method in the paper.The results showed that the Ea of NR mixed with CMCS was higher than that of ammonification NR,and the thermal stability of NR improved with increasing the addition level of CMCS.

Abstract: The molecular structure, molecular weight and its distribution, P₀, PRI, Mooney viscosity, processibility of raw natural rubber, curing characteristics of compounds and mechanical properties of vulcanites were studied by hot air aging. The results show that for raw natural rubber after heating at 70°C for 20 days, C = C bond of molecular chains was broken, the numbers of the C = C bond decreased, methyl oxidized, and –OH and –COOH formed. The number-average molecular weight, weight-average molecular weight and viscosity-average molecular weight decreased, the molecular weight distribution became wide. P₀, PRI, Mooney viscosity, rubber elastic torque S ', viscous torque S ", elastic modulus G', viscous modulus G" and complex viscosity η* decreased, loss factor tanδ increased. The curing rate of compound reduced and curing characteristics were inferior. The elongation at break and tensile strength decreased, and tensile stress at 300% modulus and 500% modulus did not change obvious. Anti-aging property became deteriorate.

Abstract: In this work, the cure characteristics of nature rubber (NR) dried by microwave and hot-air were analyzed by using Vulcameter. The effect of curing temperature on induction period (tC10), optimum cure point (tC90), maximum Torque (MH) and minimum induced torque (ML) were studied. The results showed that the tC10, tC90 and ML of NR dried by hot-air were bigger than those of NR dried by microwave, however, the MH of former was bigger. And the tC10, tC90 of NR dried by microwave or hot-air can fitted Arrhenius equation well, the K1, K2 and K of Arrhenius equation coefficient for NR dried by microwave were all bigger than those of NR dried by hot-air. With the increasing of curing temperature, the MH of NR dried by microwave or hot-air decreased gradually and its trend was well satisfied with linear relationship, and the MHo of NR dried by microwave was bigger than hot-air drying.