Hindered amine light stabilizers compatability

Another specific requirement for next-generation systems is better component compatibility (23,24). The use of a silicone backbone for a stabilizer, as shown in Fig. 4.42, addresses the need to have more compatible chemical species for light stabilizers. With increased compatibility between polypropylene and the hindered amine light stabilizer, increased efficiency was noted alone with a substantial increase in extraction resistance to most common solvents. For filled polypropylene as mentioned above, the stabilizer had a reduced migration rate into fillers. This increased polypropylene to light stabilizer compatibility maintained efficiency by avoiding coadditive interactions. 

Although superior to Neoprene and Hypalon , NBR/PVC blends do not have as great resistance to UV light as pure PVC. Thus, nonblack compounds should be protected with titanium dioxide and UV light absorbers. The latter have been commonly chosen from the benzotriazole class. New hindered amine stabilizers have been introduced (e.g., NOR HALS 833 from Ciba), that are resistant to hydrogen chloride. These should be considered for NBR/PVC compounds (except if tin mercaptide stabilizers are used). All NBR/PVC compounds should contain antioxidants of broad compatibility (e.g., Irganox 1076). 

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