Study on the ozone aging mechanism of Natural Rubber

• Published in: Polymer degradation and stability Vol. 186; p. 109514
• Main Authors: Zheng, Tingting, Zheng, Xiaoqian, Zhan, Shengqi, Zhou, Jing, Liao, Shuangquan
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 01.04.2021; Elsevier BV
• Subjects: Aging; Aging (natural); Antioxidants; chemical structure; degradation; Free radicals; Mechanical properties; Molecular structure; Natural rubber; Ozone; ozonolysis; polymers; Rubber; squalene; structure; natural rubber; ozone; structure; mechanical properties
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2021.109514

•The mechanism of ozone aging for natural rubber was systematically studied in this work.•During the ozone aging process, three new free radicals were found.•This work can provide a proof-of-principle concept for understanding the mechanisms of ozone aging and new ideas for the design of high-efficiency antioxidants for cured neat NR. Regarded as a strategically crucial material, natural rubber (NR) plays an essential role in our daily life. However, the corresponding rubber products have been facing the problem of aging in which the ozone aging of natural rubber accounts for a crucial position. Based on the concern, the related mechanism of ozone aging for natural rubber was systematically studied in this work. Besides, to deeply understand the mechanism of ozone aging, we selected squalene, a small molecular substance with similar structure to natural rubber, to simulate the ozone aging process and analyze the molecular structure changes of natural rubber. After comprehensive characterization, the obtained results showed that the natural rubber molecular network, during the aging process, was destroyed and three newly-discovered free radicals were generated (•H, •O2−and •C=C), finally resulting in the weakened mechanical properties. We believe this work can provide a more insightful view toward the relevant research on the ozonolysis mechanism and the relationship between structure and performance as well as new ideas for the design of high-efficiency antioxidants for NR.