Production of Vinylidene Chloride from the Thermal Decomposition of Methyl Chloroform

Abstract

This study investigated the extent to which methyl chloroform undergoes thermal decomposition to form vinylidene chloride. The experiment was conducted under laboratory conditions that approximate those found in industrial environments. Methyl chloroform vapors at approximately the TLV concentration of 1910 mg/m3 were passed through a heated quartz tube packed with glass or copper beads. In the presence of glass, the decomposition reaction began at 350 degrees C and was essentially complete at 605 degrees C. Vinylidene chloride was detected in nearly stoichiometric amounts. In the presence of copper, the reaction occurred initially at 180 degrees C. At 442 degrees C no methyl chloroform was detected. Once again, the conversion to vinylidene chloride was nearly complete. Two major conclusions have been derived from this study. First, under these experimental conditions, methyl chloroform undergoes thermal decomposition to yield substantial quantities of vinylidene chloride. Second, the dehydrohalogenation reaction proceeds at much lower temperatures in the presence of copper.

Metal-Coordination-Induced Fusion Creates Hollow Crystalline Molecular Superstructures

“…No other chlorine species were observed. The binding energies (Cl – 2p 3/2 = 198 eV and Cl – 2p 1/2 = 199.2 eV) are consistent with the formation of a copper chloride salt such as (NH 4 )­CuCl 3 , as indicated by powder X-ray diffraction (PXRD) ( vide infra ). , Such salts can be formed from reactions between the solvents and copper ions. − The absence of Na + and K + peaks excludes the presence of common impurities (e.g., NaCl, KCl).…”

An Experimental Comparison of the Thermal Destruction of Gaseous and Liquid 1,1,1-Trichloroethane

“…Glisson et al (1986) detected C,HCI as a product in all runs above 850 K and in some runs at temperatures as low as 775 K. We looked for but did not detected C,HCI for our experimental conditions. Phosgene (CCl,O) was observed as a byproduct of combustion for all runs above 900 K in our previous I, I, l-trichloroethane studies .…”

Health hazard evaluation report: HETA-86-343-1822, Sheller-Globe (Allen Industries, Inc.), Herrin, Illinois.

“…Chronic exposure may result in liver and kidney damage. 3 Animal studies have shown inhalation of vinylidene chloride can cause angiosarcoma at low exposure levels. NIOSH recommends that occupational exposure be reduced to the lowest feasible level.…”

“…Additionally, since a recent laboratory study had revealed that vinylidene chloride is a primary product resulting from the thermal decomposition of 1,1,1-trichloroethane, samples were collected to assess exposure to this substance. 3 Samples for these substances were collected at a flow rate of approximately 50 cc/min using a charcoal tube collection media. Each sample tube was analyzed for 1,1,1-trichloroethane and vinylidene chloride by gas chromatography with a flame ionization detector in accordance with NIOSH Method No.…”