CALCULATION OF ROTATIONAL BARRIERS IN AMORPHOUS POLYMERS

The Monte Carlo method was used for generation of amorphous polyethyle ne configurations on a diamond lattice. Chain building was performed o n the tetrahedral lattice of edges 36, 62 and 43 Angstrom with periodi c boundary conditions imposed. 32 chains were generated, each with a l ength of 100 CH2-groups (resulting density = 0.81 g . cm(-3)). Small s pherical volumes with a radius of 10 Angstrom were chosen at random fr om the total volume for the calculation of relational barriers. The ro tating bond was chosen to be close to the center of this sphere. We em ployed the method of molecular mechanics in order to calculate the rot ational barriers. The calculation was made for 578 rotating bonds and the obtained distribution of rotational barriers is approximated by th e corresponding Gamma-distribution.