| 摘要 |
<p>Monomers of formula X-CH=CH-OR where X is halogen and R is an aliphatic, cycloaliphatic or aromatic group containing up to 10 carbon atoms may be polymerized to high molecular weight polymers having a steric regularity of structure in the presence of a catalyst of formula MeX1nYm [Z]p in which Me is an element belonging to Group II, III, IV or V of the Mendel</>eeff Periodic Table, X1 is a halogen, Y is an alkyl, alkoxy, acyloxy, aryl, aryloxy, aralkyl, cycloalkyl or cycloalkoxy group, Z is a Lewis base, m and n are O or an integer and m+n is the valency of Me and p is O or an integer. Specified ethers include chlorovinyl methyl, ethyl, isopropyl, butyl, isobutyl, cyclohexyl and benzyl ethers; bromovinyl methyl, ethyl, isobutyl, tolyl, cyclohexyl and phenyl ethers; and iodovinyl methyl and ethyl ethers; which may be in the cis or trans forms. Polymerization may be effected in an inert liquid medium, e.g. toluene, and specified catalysts include aluminium trialkyls; dialkyl aluminium halides such as diethyl aluminium chloride; alkyl aluminium dihalides; boron trifluoride etherate; titanium, zirconium or vanadium dihalogen dialkoxides; titanium, zirconium or vanadium dihalogen diacetates; titanium dihalo dicyclopentadienyls and their complexes with alkyl aluminium compounds, alkyl aluminium halides and aluminium trichloride. The products are said to have threo-di-isotactic and erithro-di-isotactic structures. They may be used in the manufacture of shaped articles such as films, fibres and filaments which may be oriented by stretching. Specification 928,155 is referred to.</p> |
