Patent GB-927817-A (GB)
Title: Improvements in or relating to a process for polymerization of epoxides
IPC: C08G65/12
Filed: 1961-03-10
Abstract: A catalyst for polymerizing epoxides (see Group IV(a)) comprises the reaction product of a dihydrocarbon zinc with a polyfunctional compound which is either (a) water, (b) a non-aromatic polyol, wherein there is at least one carbon between two of the COH groups, or (c) a polyhydric phenol, the mol ratio of polyfunctional compound to zinc compound being from 0,2: 1 to 1,2: 1.  The preferred zinc compounds are the dialkyls; also mentioned are dicyclohexyl, dicyclopentadienyl and diphenyl zinc. Examples of polyfunctional compounds (b) and (c) are tri-, tetra- and penta-methylene glycols, 2-butene-1, 4-diol, 2-butyne-1, 4-diol, 1, 3- and 1, 4- cyclohexanediols, resorcinol, hydroquinone, catechol, pyrocatechol, pyrogallol, glycerin, pentaerythritol and 4, 41- thio bis (6-tert. butyl-m-cresol).  A complexing agent such as diethyl ether, tetrahydrofuran, a tertiary amine or a tertiary phosphine may be introduced either during the reaction to form the catalyst or afterwards.  The catalyst may also be prepared in situ in the polymerization reaction mixture.ALSO:Oxirane compounds are polymerized to high molecular weight by contacting with a catalyst prepared by reacting a dihydrocarbon zinc with a polyfunctional compound consisting of (a) water, or (b) a non-aromatic polyol, wherein there is at least one carbon between two of the COH groups, or (c) a polyhydric phenol; the mol. ratio of the polyfunctional compound to the zinc compound being from 0,2:1 to 1,2:1.  Examples of oxirane compounds are ethylene, propylene, 1- and 2-butene, isobutylene, 1-hexene, cyclohexene and styrene oxides, glycidyl ethers of phenol and bis-phenol, vinyl cyclohexene mono- and di-oxides, butadiene monoxide, allyl glycidyl ether, epihalohydrins, trifluoromethyl ethylene oxide, perfluoropropylene oxide and perfluoroethylene oxide.  They may be homo-or co-polymerized.  The preferred zinc compounds are zinc dialkyls; also mentioned are dicyclohexyl, dicyclopentadienyl and diphenyl zinc.  Examples of polyfunctional compounds (b) and (c) are tri-, tetra- and penta-methylene glycols, 2-butene-1,4-diol, 2-butyne-1,4-diol, 1,3-and 1,4-cyclohexanediols, glycerin, pentaerythritol, 4,41-thiobis(6-tert-butyl-m-cresol), pyrogallol, resorcinol, hydroquinone and catechols.  The catalyst may be pre-formed or prepared in situ in the polymerization mixture.  The initial reaction product may also be reacted with a complexing agent, e.g. diethyl ether, tetrahydrofuran, a tertiary amine or a tertiary phosphine. Polymerization may be effected batchwise or continuously, in bulk or in a diluent.  The monomers and/or the catalyst may be added all at once or intermittently.  Additives such as anti-oxidants, carbon black, zinc stearate and sulphur may be present.  Examples are given of the preparation and purification of polymers of ethylene oxide, propylene oxide, 1-butene oxide, epichlorhydrin, copolymer of ethylene oxide and epichlorhydrin, and copolymers of propylene oxide and allyl glycidyl ether.  Some of these are rubbery, and in Example 7 a copolymer of propylene oxide and allyl glycidyl ether is vulcanized with conventional agents.  The polymers include crystalline fractions, and their RSV's are given.