According to the mechanism of propylene polymerization

the process simulation for liquid phase bulk propylene polymerization in loop reactor was carried out by using Polymers Plus of ASPEN with the method of response surface methodology(RSM). The method of Levenberg-Marguardt was used in the GPC (Gel Permeation Chromatography) curve deconvolution of the polypropylene sample to calculate the active sites of Ziegler-Natta catalyst. The result showed that the catalyst was characterized by assuming existence of five active sites. By using Monte Carlo method

the multi-site's dynamic data was gotten on the base of a new model in which the catalyst was assumed as uniform sphere and the integral was made. The individual and interactive effects of temperature

pressure

mass flow of catalyst

mass flow of propylene

and volume fraction of hydrogen on Mw of PP was investigated and a quadratic model was developed for the prediction of Mw of PP. The Mw predicted by quadratic model was 2.142×105 very close to the experimental data with the deviation of 1.25%. The quadratic model and 3D tendency curves can be used to optimize operation and to improve PP quality conveniently.