Chain molecules, degradation orientation

Mobility of the reactants and reaction products of the oxidative kinetic chain reaction, of stabilisers and of the polymer molecules themselves affects the kinetics of the radical reactions. Morphology of a polymer material and its physical state, e g. stress, strain and orientation, has an effect on the mobility and therefore on the process of oxidative degradation. Fibres or slit films of polyethylene or pol ropylene are cold-drawn in the production. The orientation of the cold-drawn polymer material produced here has a particularly strong repercussion on oxidation stability. 

The preliminary results show that a linear correlation exists between optical activity of initial polymers and their degradation products and thus, the latter reflect the structure of the polymer chain. From mechanistic point of view this study of cis monomers supports the important concept that the chiral initiator is not only able to distinguish between two enantiomeric molecules (stereoelective process) but is able to recognize an asymmetric carbon of parent configuration and to orientate the attack on the neighbouring one. This is the caracteristies of a "regioselective process and it opens a field of the study of differently disubstituted monomers leading to various diastereo-isomeric structures. 

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