Abstract
In this research, molecular dynamics simulation is adopted to simulate the molding filling in nano-injection molding process. Our work divided into two parts is as follows.(I) Glass transition temperature : Molecular dynamics is adopted to simulate the glass transition temperature of polypropylene at different chain length, and the chain length has 200, 400 and 800, respectively. The simulated purpose is to explore the relation between the chain length(molecular weight) of polymer and the glass transition temperature of polymer.(II) We adopt molecular dynamics to simulate the nano-scale injection molding process, and investigate the defects during molding filling process. With decreasing the injection velocity, the adsorption phenomena at the entrance of mold will become more obvious. The orientation of polymer is obvious at the wall of runner and the wall which faces the entrance of mold. While the temperature of system at 350 K, polymer has less tendency to adsorb on the wall.