For high viscosity bulk-copolymerization of octamethylcyclotetrasiloxane and amino-silicone monomer, a multisyphon flow physical model was established.Based on the free volume and chemical reaction kinetic theories, a...For high viscosity bulk-copolymerization of octamethylcyclotetrasiloxane and amino-silicone monomer, a multisyphon flow physical model was established.Based on the free volume and chemical reaction kinetic theories, a new computational model was developed to simulate the multisyphon flow model. As to the new model, the united influence of reaction and diffusion was reviewed and analyzed. The new model was used to simulate bulk- copolymerization of octamethylcyclotetrasiloxane and amino-silicone monomer and agreed well with the results.展开更多
The elementary reactions of propylene polymerization catalyzed by conventional Ziegler-Natta catalysts was proposed according to the comprehensive view and without considering the effect of any impurity in the materia...The elementary reactions of propylene polymerization catalyzed by conventional Ziegler-Natta catalysts was proposed according to the comprehensive view and without considering the effect of any impurity in the material on propylene polymerization. The Monte Carlo simulation technique was employed to investigate the kinetics of propylene polymerization in order to determine the validity of the stationary state assumption and the effects of the polymerization temperature on the polymerization. The simulated total amount of active species, which only increases quickly at the beginning of the polymerization, indicates that the stationary state assumption in the studied system is valid. Moreover, significant effects of polymerization temperature on the polymerization conversion, and the molecular weight and its distribution were also analyzed. The simulated results show that the consumption rate of propylene increases with the increase of polymerization temperature; the maximum values of the number-average degree of polymerization are constant at different polymerization temperatures, however, the peak appears earlier with the higher temperature; as the polymerization temperature increases, the average molecular weight decreases and the molecular weight distribution changes greatly.展开更多
文摘For high viscosity bulk-copolymerization of octamethylcyclotetrasiloxane and amino-silicone monomer, a multisyphon flow physical model was established.Based on the free volume and chemical reaction kinetic theories, a new computational model was developed to simulate the multisyphon flow model. As to the new model, the united influence of reaction and diffusion was reviewed and analyzed. The new model was used to simulate bulk- copolymerization of octamethylcyclotetrasiloxane and amino-silicone monomer and agreed well with the results.
基金The National Natural Science Foundation of China(No.20406016)the Project of Fujian Petrochemical Company of SIN-OPEC (No.MS/FJ-08-JS-15-2005-01).
文摘The elementary reactions of propylene polymerization catalyzed by conventional Ziegler-Natta catalysts was proposed according to the comprehensive view and without considering the effect of any impurity in the material on propylene polymerization. The Monte Carlo simulation technique was employed to investigate the kinetics of propylene polymerization in order to determine the validity of the stationary state assumption and the effects of the polymerization temperature on the polymerization. The simulated total amount of active species, which only increases quickly at the beginning of the polymerization, indicates that the stationary state assumption in the studied system is valid. Moreover, significant effects of polymerization temperature on the polymerization conversion, and the molecular weight and its distribution were also analyzed. The simulated results show that the consumption rate of propylene increases with the increase of polymerization temperature; the maximum values of the number-average degree of polymerization are constant at different polymerization temperatures, however, the peak appears earlier with the higher temperature; as the polymerization temperature increases, the average molecular weight decreases and the molecular weight distribution changes greatly.
