Phosphorous based derivatives (phosphites and phosphonites) are well known
to be effective as polymer stabilisers mainly during processing, acting as
secondary antioxidants and are particularly effective in combination with p
henols (primary antioxidants). In addition some phosphites and phosphonites
can help in improving the discoloration of polymer articles when they are
exposed to heat, UV light, nitrogen oxides (gas fading) and to gamma rays.
However, phosphorous based stabilisers are sensitive to heat and moisture s
o they can cause undesired side problems during processing and in the life
time of polymer articles making useless their benefits. The aim of this stu
dy is to test a new phosphite compound more hydrolytically stable than the
commercial ones and to present its outstanding performances in improving di
scolouration during processing as well as when polymer articles are exposed
to gamma rays. The comparison has been carried out with standard available
products. (C) 2001 Elsevier Science Ltd. All rights reserved.