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

EPR and DSC Study of the Decay of Allyl Macroradicals in Chemically Crosslinked Polyethylene

M. Klímová, J. Bartoš, and F. Szöcs

Polymer Institute, Slovak Academy of Sciences, CS-842 36 Bratislava

Abstract: The decay of allyl macroradicals in chemically crosslinked polyethylenes was studied as a function of the chemical crosslinking and temperature by the EPR method. The decay rate constant was found to decrease in the temperature range between 293 and 323 K with the increasing gel fraction until the reaching of stable value at higher crosslinkings. On the other hand, the rate constant for decay increases monotonously with temperature in the region of lower gel fractions but within the region of higher gel contents its increase is stepwise. Dependences of the rate constant on the gel content are closely associated with the structural-chemical changes of the amorphous phase caused by the crosslinking of macromolecules. Temperature dependences of the rate constant are influenced by the course of phase change indicated by compensation effect and proved by DSC technique.

Full paper in Portable Document Format: 461a20.pdf

Chemical Papers 46 (1) 20–23 (1992)