MONTE-CARLO STUDIES OF THE CONFORMATIONAL STATISTICS OF POLYMERS POLYETHYLENE

The conformational distribution of unperturbed polyethylene (PE) has b een studied utilizing the Monte Carlo approach. The results are in exc ellent agreement with experiments on the average dimensions of PE chai ns, as well as with the molecular scattering function obtained in mixt ures of deuterated and hydrogenous PE at 400 K. Maps of the free energ y as a function of two consecutive torsional angles confirm that an ap proximate description of the conformational distribution of PE can be given in terms of three rotational isomeric (RIS) states. The location of the states and the corresponding energy and entropy parameters, wh ich can be separately evaluated from the Monte Carlo results, are comp ared with literature results obtained by internal energy calculations for butane and pentane.