Sn. Kreitmeier et al., MOLECULAR-DYNAMICS SIMULATIONS OF MACROSCOPIC VIBRATIONS ON COOLING OF SUPERHEATED POLYETHYLENE CRYSTALS, Polymer international, 36(2), 1995, pp. 155-163
In this paper a discussion is given of the change of density with time
and temperature within a crystal of 192 (CH2)(50) chains, simulated b
y molecular dynamics computations at temperatures from 65 to 425 K. Th
e highest temperatures exceed the melting temperature (about 365 K). O
n simulation for times of up to 100 ps the temperature dropped through
the melting temperature, permitting the study of the behavior of the
crystal during initial melting, followed by limited recrystallization.
In these short times only a limited number of chains on the surface c
an begin to coil and melt conformationally, but there is an indication
of a disordering transition. A better comparison with experimental da
ta on density, expansivity and speed of sound is possible.