GB765054A - Solid polymers of propylene oxide - Google Patents

Abstract

Epoxides at least 50 per cent by weight of which is propylene oxide are polymerized to yield solid polymers melting above 50 DEG C. The propylene oxide may be copolymerized with ethylene oxide, epichlorhydrin, isobutylene oxide, 1,2-epoxybutane, cis. or trans. 2,3-epoxybutane or styrene oxide. Polymerization may be effected en masse or in a non-aqueous liquid, e.g. diethyl ether, di-isopropyl ether, petroleum ether, benzene or n-hexane. The catalysts are certain iron compounds, e.g. hydrated ferric hydroxide, basic ferric acetate, ferric chloride hexahydrate, ferrous chloride tetrahydrate, ferric bromide, or complex compounds made by the controlled reaction of anhydrous ferric chloride with a limited amount of propylene oxide (see Group IV (b)). Monomers may be purified by removing water with anhydrous CaSO4 and distilling. Aldehyde may be removed by fractional distillation of the oxide in contact with alkali metal hydroxide. The products are preferably stabilized against decomposition by incorporation of a phenol or aromatic amine antioxidant, several of which are specified. Incorporation may be by mixing with molten resin or with solid resin preferably immediately after recrystallization while it is still soft with solvent. Products are useful for making films, which may be oriented by stretching. Films may be made by extrusion or by casting, e.g. from a solution in tetrahydrofuran. In examples: (1) propylene oxide was polymerized in a glass-lined autoclave by stirring with an anhydrous ferric chloride-propylene oxide complex at 80 DEG C. The brown rubbery solid dissolved in hot acetone was rinsed with sufficient HCl to convert the iron complex to soluble ferric chloride. Cooled to - 20 DEG C. the solution deposited crystals of polymer which were recrystallized from acetone. The product had a molecular weight of 135,000. 4.41-Isopropylidene phenol was added as antioxidant and the mixture moulded to a clear film which was stretched longitudinally. (2) Ferric chloride hexahydrate was used as catalyst. (3) Ferric hydroxide was used as catalyst. (4) A series of polymerizations in solvents are described. (5) Propylene oxide and epichlorhydrin were copolymerized with ferric hydroxide catalyst. (6) and (7) Co-polymerisations are described with ethylene oxide, epichlorhydrin and styrene oxide, isobutylene oxide, 1,2-epoxy butane and cis. and trans. 2,3-epoxy butane.ALSO:Complex compounds are made by reaction of anhydrous fabric halide with a limited amount of propylene oxide. They may be mixtures of 2FeCl3.C3H6O; FeCl3.C3H6O; FeCl3.2C3H6O; and FeCl3.3C3H6O. The products are prepared by gradually adding propylene oxide to anhydrous ferric chloride, e.g. dissolved in diethyl ether, with stirring and cooling until there is a further immediate evolution of heat. They are catalysts for polymerizing propylene oxide (see Group IV (a)).