Model Development for Copolymerization Process of Ethylene and Norbornene At Elevated Pressure

Model Development for Copolymerization Process of Ethylene and Norbornene Copolymer at Elevated Pressure

Zhen Yao*, Binbin Dai , Bing Xie, Kun Cao

¹ State Key Laboratory of Chemical Engineering(ZJU), Institute of Polymerization and Polymer Engineering, Department of Chemical Engineering, Zhejiang University, Hangzhou 310027, China

Process model for ethylene and norbornene(NB) copolymerization at elevated pressure were developed by considering the variation of active site concentration and the influence of mass transfer process. The parameters were validated by batch polymerization. The polymerization experiment was taken place in a 2L agitated reactor, in which the effect of mass transfer process on ethylene and norbornene concentration can not be ignored. As a result, a physical model for mass transfer process was provided. It is assumed that a concentration gradient is limited in numerous spherical regions which take the catalyst active site as its centre after the reaction starts. Besides, as norbornene has a negative affect on catalyst activation, a relationship between the catalyst active site concentration and the norbornene concentration was developed. The polymerization rate, copolymer composition and ethylene dissolving rate were predicted and compared with the experimental data. Further calculation on the viscosity and the instantaneous NB/E monomer ratio were developed. The copolymer composition distribution(CCD) was predicted and compared with the copolymer characteristic results. Finally, by using designed policy to vary ethylene pressure, copolymers with narrow CCD were produced.

---

* Corresponding authors. Zhen Yao: yaozhen@zju.edu.cn