Acta Phys. -Chim. Sin. ›› 2009, Vol. 25 ›› Issue (07): 1373-1378.doi: 10.3866/PKU.WHXB20090719

• ARTICLE • Previous Articles     Next Articles

Molecular Simulation of Oxygen Adsorption and Diffusion in Polypropylene

TAO Chang-Gui, FENG Hai-Jun, ZHOU Jian, LV Ling-Hong, LU Xiao-Hua   

  1. Guangdong Provincial Key Laboratory for Green Chemical Product Technology, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, P. R. China|State Key Laboratory of Materialsoriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009, P. R. China
  • Received:2009-02-23 Revised:2009-03-30 Published:2009-06-26
  • Contact: ZHOU Jian E-mail:jianzhou@scut.edu.cn

Abstract:

Grand canonical Monte Carlo and molecular dynamics simulations were used to study the adsorption and diffusion of oxygen in polypropylene (PP). It is found that at roomtemperature, the loading of oxygen in PP increases and the diffusion coefficient of oxygen in PP decreases as the polymerization degree of PP increases. The loading and diffusion coefficient reach platform values when the polymerization degree of PP is relatively high. The loading of oxygen decreases and the diffusion coefficient of oxygen in PP increases as the temperature increases. The oxygen diffusion mechanism in PP is also discussed according to free volume theory. Oxygen molecules firstly oscillate inside one cavity of PP and then jump from this cavity to another one through a channel formed by the thermal motion of PP chains. In general, simulation results indicate that polymer materials with a high degree of polymerization used at room or low temperatures should be preferred in food reservation technology. This work provides some guidance and basis for developments in food packing materials.

Key words: Gas, Polymer, Molecular dynamics, Molecular simulation, Diffusion

MSC2000: 

  • O641