Does 6PPD ozonation pose ecological risks?

Please reconnect 6PPD, a tire rubber antioxidant, poses substantial ecological risks because it can form a highly toxic quinone transformation product (TP), 6PPD-quinone (6PPDQ), during exposure to gas-phase ozone. Important data gaps exist regarding the structures, reaction mechanisms, and environmental occurrence of TPs from 6PPD ozonation.

What are 6PPD reactions with ozone?

6PPD reactions with ozone generate numerous ubiquitous and potentially bioactive transformation products that can be detected in tire rubber particles and roadway environments.

Does 6ppdq occur during ozonation of 6qdi?

Consistent with prior findings, 6PPDQ (C 18 H 22 N 2 O 2) was one of the major TPs in 6PPD ozonation (∼1 to 19% yield). Notably, 6PPDQ was not observed during ozonation of 6QDI (N – (1,3-dimethylbutyl)- N ′-phenyl- p -quinonediimine), indicating that 6PPDQ formation does not proceed through 6QDI or associated 6QDI TPs.

How is ozonation of 6PPD characterized?

To address these data gaps, gas-phase ozonation of 6PPD was conducted over 24–168 h and ozonation TPs were characterized using high-resolution mass spectrometry. The probable structures were proposed for 23 TPs with 5 subsequently standard-verified.

What are the data gaps in 6PPD ozonation?

Important data gaps exist regarding the structures, reaction mechanisms, and environmental occurrence of TPs from 6PPD ozonation. To address these data gaps, gas-phase ozonation of 6PPD was conducted over 24–168 h and ozonation TPs were characterized using high-resolution mass spectrometry.