摘要
Molecular dynamics (MD) simulations of atactic poly (methyl methacrylate) (PMMA) in the bulk amorphous state were carried out. The non-Gaussian parameters A and the mean square displacements were calculated to investigate the heterogeneity and space distribution for chain dynamics of PMMA. The results indicate that fast moving atoms of the PMMA chain assemble each other in the system. The free volume in PMMA was also evaluated and the pair-correlation functions between the free volume and mobile atoms of PMMA were calculated. The MD simulations revealed that the free volume was distributed near atoms having fast mobility in the glass state of PMMA. © 2010, The Society of Polymer Science.