Phosphoryldithioformates as spin trapping agents and process stabilizers - 3

Five new phosphoryldithioformates bearing different substituents on the phosphoryl group have been synthesised and exploited as spin trapping agents in ESR experiments. While the dilauroxy substituted compound led to the observation of ESR spectra indicating photolability of either the compound as such or of its radical adducts, the three diaryloxy-phosphoryl dithioformates exhibited an excellent spin trapping ability, thus proving an attractive alternative to previously described members of this family. This was also the case for the di(2-menthoxy)-phosphoryl derivative which led in all cases to very persistent radical adducts. The low melt-flow index values measured in the extrusion of polypropylene with variable additions of some of the dithioformates investigated in this and in previous studies indicated that the tested compounds have a remarkable ability to act as process stabilisers.