The invention relates to thermoplastic molding compositions comprising a polycarbonate resin which is rendered resistant to gamma radiation induced yellowing. It was surprisingly found that the incorporation in the resin of an effective amount of benzylic alcohol or its derivatized versions renders the composition resistant to yellowing. The composition of the invention is suitable for the preparation of molded articles having improved resistance to yellowing and to the formation of haze induced upon exposure to gamma radiation.
ANION RADICAL-INDUCED DESILYLATION OF ORGANOSILANE. REACTIONS OF BENZYLSILANES WITH ALDEHYDES AND RELATED COMPOUNDS IN THE PRESENCE OF BUTYLLITHIUM OR LITHIUM METAL
By the action of butyllithium or lithiummetal in such polar aprotic solvent as DMF or HMPA in the presence of aldehydes or related compounds, some benzylsilanes suffer from anion radical-induced desilylation forming benzyl carbanions which add to the aldehydes and related compounds.
Desilylation of α-alkoxysilanes offers the convenient generation of carbinyl carbanions which react with a variety of carbonyl compounds giving mono-protected 1,2-diols of unsymmetrical type. Dehydration of these unsymmetrical diols leads to the regioselective formation of methyl ketones.