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

Per‐2,3‐acetyl‐β‐cyclodextrin is first synthesized by selective modification and used as core molecule for preparing a star‐shaped macromolecular antioxidant (β‐CD‐DBHMP) via a two‐step method. β‐CD‐DBHMP is characterized by 1H‐NMR, MALDI‐TOF MS, and TGA. The performance of β‐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 β‐CD‐DBHMP with a Mn of 4.03 × 103 g · mol−1 is successfully obtained, and it possesses high thermal stability with an initial weight loss temperature of 290 °C. Moreover, β‐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.