Comparative analysis of the physicochemical, toxicokinetic, and toxicological properties of ether-PFAS.

Perfluoropolyethers, also known as ether-PFAS, are linear or branched alkyl ether polymers, where the substituent hydrogens on the carbon atoms in the chain have been fully replaced by fluorine atoms. Some of these molecules may have a carboxylate functional group attached to one of the terminal carbon atoms to form an ether-PFAS carboxylate. Perfluoropolyethers are used as processing aids in the manufacture of various types of perfluorinated polymeric materials which are used in a variety of consumer applications.

Bimolecular Reactions between Dimethylnitramine and Its Radical Decomposition Products.

Bimolecular reactions between intact nitramines and their radical decomposition products can accelerate thermal decomposition, yet the detailed mechanisms of such reactions are not well understood. We have used density functional theory at the M06/6-311++G(3df,3pd) level to locate transition structures and compute 0 K activation barriers for various gas-phase reactions that may contribute to radical-assisted decomposition of dimethylnitramine (DMNA, (CH)NNO). Our calculations indicate that H abstraction from DMNA is the lowest-barrier mechanism for most radicals and a subsequent N-N β-scission in the alkyl radical 3 leads to an imine intermediate and NO.