In June, the European Chemicals Agency (ECHA) included the chemicals D4 (
octamethylcyclotetrasiloxane), D5 (decamethylcyclopentasiloxane) and D6 (dodecamethylcyclohexasiloxane) to the EU REACH Candidate List for Substances of Very High Concern (SVHC).
Methane supplied in gas cylinders, with purity better than 99.99% was used to deliver
octamethylcyclotetrasiloxane (D4) to the natural gas flow using custom-made pressure resistant gas bubblers.
The various endocrine disrupting chemicals are Parabens [10] UV-filters such as benzophenone-1, benzophenone-3 and octinoxate, [11-13] synthetic musks and other fragrance compounds, antimicrobials such as triclosan, cyclosiloxanes
octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6), bisphenol-A (BPA), alkylphenols such as nonylphenols and octylphenol, and glycol ethers.
Only few types of synthetic Si[O.sub.2] glass, obtained by sol--gel technology [1] or from silicon-organic raw-materials have Cl concentrations below 1 ppm (e.g., commercial types Suprasil UVL or Corning 7979, produced from
octamethylcyclotetrasiloxane OMCTS, [[[(C[H.sub.3]).sub.2]SiO].sub.4]).
A common approach to lower VOC content in solvent-based alkyd coatings is to use exempt solvents, such as acetone, methyl acetate, parachlorobenzotrifluoride (PCBTF),
octamethylcyclotetrasiloxane (D4 cyclic siloxane), and tert-butyl acetate.
The main cyclic VOSiCs present in biogases are the
octamethylcyclotetrasiloxane (D4), the decamethylcyclopentasiloxane (D5), the hexamethylcyclotrisiloxane (D3), and to a lesser extent the dodecamethylcyclohexasiloxane (D6).
Gleason, "Hotilament chemical vapor deposition of organosilicon thin films from hexamethylcyclotrisiloxane and
octamethylcyclotetrasiloxane, Journal of the Electrochemical Society, vol.
Andersen, "Modeling of human dermal absorption of
octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5)," Toxicological Sciences, vol.
Bis(3-aminopropyl)-tetramethyldisiloxane (BAPTM DS) and
octamethylcyclotetrasiloxane ([D.sub.4]) were purchased from Gelest, Inc.
[3] used Tomlinson's model to study temperature dependence of friction on n-hexadecane and
octamethylcyclotetrasiloxane and in each case his results show inverse relationship.
We therefore used
octamethylcyclotetrasiloxane (OMS; Fluka), which has a boiling point of 448 K and a chemical shift of 0.094 ppm compared with TMS.
