By this Monte Carlo simulation we studied the glass transition of polymethy
lene using the modified bond-fluctuation model combined with considering th
e rotational-isomeric state model. The configurational properties in the po
lymethylene (PM) melts, such as the mean length, the mean energy per bond a
nd the mean square radius of gyration were monitored. We found that the cha
ins cannot be in the equilibrium states after a very long time when the tem
perature of the dense PM chains decreases to 120 K. As the melt vitrifies,
these quantities gradually become independent of temperature in a narrow ra
nge. The glass transition temperature T-g depends upon the chain length of
PM chains, and extrapolation to (CH2)(infinity) gives T-g(infinity) = 212 K
. The dynamics in the PM melts was also studied. It was found that the diff
usion coefficients can be described by the Vogel-Fulcher law and the Vogel-
Fulcher temperature T-0 is 124 K. This method may be used to investigate th
e glass transition of other real polymer chains.