Abstract
In this research, molecular dynamics simulation is adopted to simulate the glass transition temperature of polyethlene and 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 polymer at different chain lengths, and the chain lengths are 100,200,400 and 800, respectively. The purpose of the simulation is to explore not only the relation between the chain length and the glass transition temperature of polymer, but also the relation between the pressure and the glass transition temperature of polymer at the same chain length. II. Unsteady nano injection molding：With increasing chain length, the density of local system gets more uniform.The probability of warpage becomes great with increasing the interaction between metal particle and polymer particle. Besides, the simulation results between Pt and Au are almost the same. However, if the injection velocity is too large, more plastics will be wasted and the filling quality is relatively bad. Finally, when the temperature is on the increase, the polymer gets easier to be processed and the density in the mold gets more uniform.