Research And Synthesis Of Hindered Amine N-Oxyl Light Stablizers

Hindered Amine Light Stabilizers (HALS) have capabilities of capturing free radicals, decomposing peroxides. Their light stability effect is much better than UV absorbents, and at the same time they have the performance of anti-polymerization. As a stabilizer used in polymers to prevent the light aging and delay their using life, HALS has the largest quantity, the most wide applied field, and the best developing outlook. Since its birth in late seventies, HALS was widely developed and applied, and became one of the fastest developing agents.With two methods: direct oxidization and transesterification, we synthesized three new kinds of hindered amine N-oxyl light stabilizers which have not been reported domestically. As low-alkali or non-alkali comes true, the N-oxyl light stabilizers have more widely applied field, more excellent performance, and more easily used with other stabilizers.The methods we selected are relatively simple, the material is easily acquired, the experiment condition is mild, the reagents used have lowtoxicity, and the products come into being crystal easily which makes separation and purification convenient. In experiment the conditions such as time, ratio, solvent, concentration, and catalyst dosage were discussed by the numbers. So we find out the best experiment condition, and satisfying result is acquired. The yield of direct oxidization is 80%, and that of transesterification is 86%. Furthermore, the structure of the products are validated by testing mp., element analyzing, ESR, FT-IR, ESI-MS, NMR etc.Finally, we simply discussed the mechanism of the two methods theoretically in the hope that it can provide theoretical foundation for more deeply researching new synthesis ways of HALS.