Synthesis of A Star-Shaped Macromolecular Antioxidant Based on -Cyclodextrin and its Antioxidative Properties in Natural Rubber

Per-2,3-acetyl--cyclodextrin is first synthesized by selective modification and used as core molecule for preparing a star-shaped macromolecular antioxidant (-CD-DBHMP) via a two-step method. -CD-DBHMP is characterized by H-1-NMR, MALDI-TOF MS, and TGA. The performance of -CD-DBHMP as antioxidant for natural rubber is determined by OIT and accelerated thermal aging test, and its extraction resistance is also investigated. The results show that -CD-DBHMP with a Mn of 4.03x10(3) gmol(-1) is successfully obtained, and it possesses high thermal stability with an initial weight loss temperature of 290 degrees C. Moreover, -CD-DBHMP is superior to DBHMP for the stabilization of NR against thermal oxidation, and exhibits better extraction resistance. Its possible antioxidative mechanism is also discussed.