ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Molecular aspects of intramolecular hydrogen abstractions in solid polymers

J. Bartoš, P. Šimon, and L. Valko

Polymer Institute, Centre for Chemical Research, Slovak Academy of Sciences, CS-842 36 Bratislava

Abstract: In this paper the molecular aspects of 1.2—1.5 intramolecular transfers of the radical centre by hydrogen abstraction are stipulated within the scope of rotation-isomerization model. A set of criteria which enables us to determine the principal allowableness of these transfers depending on phase state of the polymer matrix has been formulated. The obtained results may be used for further analysis on the basis of activation-energy approach. An example of application is demonstrated for polyethylene. It has been revealed that these modes of chemical transport of the radical centre may, in principle, proceed in amorphous zones of the semicrystalline matrix but the estimates of energy barriers when compared with the experimental activation energies for the decay of the alkyl centres show that these modes do not play a dominant role. On the other hand, the migration of free valence along the chain does not proceed in the crystalline phase in conformity with special experiment.

Full paper in Portable Document Format: 392a271.pdf

Chemical Papers 39 (2) 271–284 (1985)