Papers by Author: Hong Xing Gui

Abstract: In this work, thermogravimetry (TG) and Wallace plastometer were used to study the thermal-oxidative aging resistance properties of natural rubber (NR) dried by microwave and hot-air. Showed from the results, thermal degradation temperature, primary thermal-oxidative degradation temperature, the value of P0, PRI and VR for NR dried by microwave were higher than those of NR dried by hot-air; the thermal-oxidative aging resistance properties of NR vulcanizes dried by microwave improved significantly, and the rate of change for elongation at break (-26.76%) and tensile strength (-38.6%) of NR vulcanizes dried by microwave before and after aging were apparently higher than those of NR vulcanizes dried by hot-air, which were (-60.29%) and (-82.11), respectively.

Abstract: In this work, effect of carboxymethyl chitosan (CMCS) on vulcanization kinetics of natural rubber was studied using the Rheometer MDR2000.The results showed that both the rate constants of induction period and curing period of natural rubber (K-N) was greater than that of natural rubber added CMCS and the dosage is 0.05% of fresh latex (CMCS-1), but less than that of natural rubber added CMCS and the dosage is 0.1% of fresh latex (CMCS-2), and the activation energy 100.8kJ/mol of induction period of K-N is greater than the activation energy 96.7kJ/mol, 93.7kJ/mol of induction period of CMCS-1, CMCS-2, respectively and that the activation energy 104.4 kJ/mol of curing period of K-N is less than the activation energy111.9kJ/mol of curing period of CMCS-1, and bigger than the activation energy 103.4 of CMCS-2 at the same temperature.

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 effect of carboxymethyl chitosan (CMCS) as preservation on cure characteristics of nature rubber (NR) was studied, which compared with NR using ammonia water as preservative agent. The results showed that the induction period and optimum cure time of sample N (Ammonia water dosage is 0.15% of the mass of fresh latex), CMCS-1(CMCS dosage is 0.05% of the mass of fresh latex) and CMCS-2(CMCS dosage is 0.1% of the mass of fresh latex) were obviously decreased with the increasing of temperature, corresponding to Arrhenius equation perfectly. The maximum torque was linear dependence on curing temperature and decreased with the increasing of curing temperature. The relation of MH0 were as follows: N>CMCS-1>CMCS-2, respectively.