| 摘要 |
Unsaturated compounds that undergo addition polymerization are polymerized at -80 to 300 DEG C. in the presence of at least 0.001%, by weight of the unsaturated compound, of one or more xenon fluorides as initiator. Specified monomers are vinyl acetate, methyl vinyl ether, butadiene, ethylene, propylene, styrene, dimethyl butadiene, acrylic and methacrylic acids, esters and amides, vinyl chloride, vinyl fluoride, tetrafluoroethylene, chlorotrifluoroethylene and hexafluoropropene. Polymerization may be effected in the presence of inert liquid media, e.g. perhalogenated hydrocarbons. In examples tetrafluoroethylene is polymerized (1) in perfluorodimethylcyclobutane in the presence of a mixture of xenon di-, tetra- and hexafluorides; and (2) in the presence of xenon tetrafluoride.ALSO:Xenon fluorides are prepared by heating a mixture of xenon and nitrogen diflouride N2F2 at 90 DEG to 100 DEG C. for 24 hours. After cooling to -196 DEG C. and removal of volatiles a white mass comprising xenon di-, tetra- and hexafluorides remains. The hexafluoride reacts vigorously with glass to give xenon tetrafluoride, which may be sublimed and is stable at room temperature. |
