MODEL QUANTUM-CHEMICAL CALCULATION OF SEN SITIVITY OF THE POLYETHYLENE CHAIN DEGRADATION WITH RESPECT TO DEFORMATION

Dependence of the activation energy for the rupture of molecules model ing the PE chain (octane and decane) on their deformation was calculat ed using the MOPAC program applying MNDO Hamiltonian. The transition s tate of such a reaction was shown to have a biradical character. The d eformation of molecules follows (within a calculation accuracy of 10%) the Hooke's law with a Young's modulus of the order of 290 HPa. The f ormation of the transient state is accompanied by similar to 0.6 Angst rom molecule elongation. A comparison of this value with data on the d urability of HDPE yields an estimate for the fraction of carrier chain s about 15%.