Hot nitric acid diffusion in fluoroelastomer composite and its degradation

Abstract

The degradation of fluoroelastomers in hot HNO3 solution included the decrosslinking via hydrolysis of crosslinks and backbone cleavages by dehydrofluorination.

Epoxy Flooring/Oil Fly Ash as a Multifunctional Composite with Enhanced Mechanical Performance for Neutron Shielding and Chemical-Resistance Applications

“…The weight gains were recorded in the fluoroelastomer and polymer composites exposed to HNO 3 and different chemicals. Jawaid et al referred to the weight gain as the OH group resulting from the water diffusion into the polymer, while Kang et al . attributed the weight gain to the acid diffusions into the material.…”

“…No weight losses were observed while exposing the samples to the chemicals, suggesting that it does not appear as if any erosion happened. 48 The weight gains were recorded in the fluoroelastomer 49 and polymer 48 composites exposed to HNO 3 and different chemicals. Jawaid et al 48 referred to the weight gain as the OH group resulting from the water diffusion into the polymer, while Kang et al 49 attributed the weight gain to the acid diffusions into the material.…”

“…48 The weight gains were recorded in the fluoroelastomer 49 and polymer 48 composites exposed to HNO 3 and different chemicals. Jawaid et al 48 referred to the weight gain as the OH group resulting from the water diffusion into the polymer, while Kang et al 49 attributed the weight gain to the acid diffusions into the material. We recorded the FTIR spectra (Figure 14) after exposure to the chemicals, and the OH group peak was not observed in the FTIR spectra, while the NO 3 and SO 4 groups were observed, as was emphasized in the discussion of the FTIR spectra (Figure 14).…”

Strengthened Poly(vinylidene fluoride)/Epoxidized Natural Rubber Blend by a Reactive Compatibilizer Based on an Amino Acid-Modified Fluorocarbon Elastomer

“…35,36 Meanwhile, the absorption bands at 889, 1136, 1179, and 1397 cm −1 are attributed to the stretching vibrations of −CF 3 −, −CH 2 −, and −CF−, respectively. 36 Regarding the spectra of modified FKM, several absorption bands appear at 1718 cm −1 for the stretching vibration of the C�O; 37 1639 cm −1 for nonconjugated C�C stretching vibration; 36,38,39 and 1560 cm −1 for C�N groups. 40,41 In addition, as the AHA content increased, the strength of the absorption bands at 2942 and Scheme 1.…”

Automatic Transmission Fluids in Electrified Transmissions: Compatibility with Elastomers

“…Characteristic FTIR spectra bands for FKM. References [37,38] are cited in the supplementary materials.…”