HYDROPEROXIDE DECOMPOSING ABILITY AND HYDROLYTIC STABILITY OF ORGANICPHOSPHITES CONTAINING HINDERED AMINE MOIETIES (HALS-PHOSPHITES)

The hydroperoxide decomposing ability and the hydrolytic stability of some HALS-Phosphite stabilisers and some of their hydrolytic transform ation products have been investigated by means of P-31 NMR spectroscop y. All HALS-Phosphites, including those bearing sterically hindered ph enolic substituents proved to be efficient hydroperoxide decomposers. HALS-Phosphites with tertiary HALS moieties are more effective than co mparable compounds with secondary HALS groups. The hydrolytic stabilit y of HALS-Phosphites is much higher than those of common phosphites. T he path of hydrolysis of HALS-Phosphites was established. In a first s tep the phenolic moieties are substituted followed by a fast removal o f one hindered piperidine group to give the corresponding hydrogen pho sphonates. These compounds are hydrolytically stable due to their beta ine structure with increased electron density at the phosphorus atom. (C) 1998 Elsevier Science Limited. All rights reserved.