New stabilisers for polymers on the basis of IPDI protected 2,2-thiobis(4-methyl-6- tert-butylphenol) and hindered amines

New thermostabilisers for polymers on the basis of a sterically hindered phenol and several sterically hindered amines (HA) were synthesised by reaction with isophorone diisocyanate (IPDI). Their thermal stability was studied by means of thermogravimetry (TG), differential thermogravimetry (DTG) and differential thermal analysis (DTA). Antioxidative properties in polypropylene were investigated in oven ageing tests using FTIR spectrometry. The compounds containing both hindered phenol and HA moiety afforded better stabilising performance in thermooxidation than two phenol moieties linked through IPDI.