GB834158A - Improvements in or relating to polyether polymers - Google Patents

Abstract

3- and 4-membered cyclic ethers used in the preparation of polyalkylene ethers (see Group IV (a)) correspond to the formul <FORM:0834158/IV (b)/1> where R is hydrogen or a radical which is inert towards cationic polymerization catalysts such as Friedel-Crafts catalysts, and has a molecular weight not greater than 250. The radicals include hydrocarbon and halogenated hydrocarbon radicals and their oxygen-substituted radicals so long as they do not contain any Zerewitinoff active hydrogen atoms and, when they do contain oxygen, it is present as an acyclic ether oxygen at least 2 carbon atoms removed from any other ether oxygen and from any halogen. They may be saturated or unsaturated, aliphatic, cycloaliphatic or aromatic, and they may be divalent, forming a ring structure with other radicals. Examples include methyl, ethyl, chloromethyl, cyclopentyl, cyclohexyl, vinyl, allyl, methallyl, 4-hexenyl, 7-octenyl, cyclohexenyl, propyloxy-, ethyloxy-, allyloxy-, phenyloxy-, 4-pentenyloxy- and 2,4-diallylphenyloxy-methyl, 4-allyloxyphenyl, 2-allyloxy benzyl and 4-allylbenzyl. The oxiranes may be prepared by monoepoxidation of mono- or di-olefinic hydrocarbons and ethers. These ethers may themselves be prepared by reacting a metal salt of a hydroxy compound with an organic halide, either or both of which may be unsaturated, e.g. allyl alcohol or higher alkenols may be condensed with such halides as n-propyl bromide, allyl bromide or phenylethyl iodide; alternatively the unsaturated alcohols may be converted into the bromide and reacted with saturated or unsaturated alcohols or phenols. The oxacyclobutanes may be prepared by ring-closing 1,3-glycol derivatives such as 1,3-halohydrins and 1,3-acetoxy halides, e.g. alcoholic alkali on pentaerythritol dichlorhydrin can yield 3-hydroxymethyl-3-chloromethyl-oxetane and/or 3-alkoxy-methyl-3-hydroxymethyl-oxetane, after which the hydroxy-methyl groups may be etherified by reaction with organic halides. Hydroxyalkyl oxetanes may also be prepared by reacting with phosgene a compound which has, in addition to a 1,3-glycol unit, one other hydroxy group on an adjacent carbon atom, to form a cyclic carbonate which is then heated with a trace of alkali or carbonate to form the 4-membered cyclic ether. No specific example is given of the preparation of these compounds but examples of compounds used include 1-allyloxy- and 1-phenoxy-2,3-epoxypropane, 3,3-bis-(chloromethyl)-oxetane, 3-ethyl- and 3-methyl-3-allyloxymethyloxetane, 3,3-diethyl-oxetane, 3 - methyl - 3 - (4 - pentenyloxymethyl) - oxetane and 3 - (4 - methyl - 4 - pentenyloxymethyl) - 3 - methyl - oxetane. Others are listed, including 2-oxaspiro-(3,5)-nonane and 2-oxaspiro-(3,4)-octane.ALSO:A millable, sulphur-curable polyalkylene ether polymer has a molecular weight of at least 30,000 and consists of the recurring units -(-CH2-CH2-CH2-CH2-O-) and <FORM:0834158/IV (a)/1> in which n is 0 or 1 and R is hydrogen or an "inert" radical having a molecular weight not greater than 250, the recurring units being connected from a carbon on one to an oxygen on another, at least one third being (CH2-CH2-CH2-CH2-O) units, and wherein there is an average of at least one R radical which contains non-aromatic carbon-to-carbon unsaturation for every 10,000 units of molecular weight of polymer. "Inert" radicals are those which are non-reactive with the catalyst used in the preparation of the polymer. They include hydrocarbon and halogenated hydrocarbon radicals and may be oxygen-substituted. Examples of unsaturated radicals are vinyl, allyl, methallyl, 4-hexenyl, 7-octenyl, cyclohexenyl, allyloxymethyl, allylphenyloxymethyl, allylphenyl, allylphenyloxy, 4 - pentenyloxymethyl, 2,4 - diallylphenyloxymethyl, 4 - allyloxyphenyl, 2 - allyloxybenzyl and 4-allylbenzyl. The polymers may be prepared by polymerizing tetrahydrofuran with at least one oxirane or oxetane of the formula <FORM:0834158/IV (a)/2> or <FORM:0834158/IV (a)/3> in the presence of a cationic catalyst. Temperatures may range from -80 DEG to 70 DEG C. Water and air are preferably excluded. Suitable catalysts are the halides of boron, aluminium, antimony and tin and certain phosphorus halides and aryldiazonium hexafluorophosphates. After the desired degree of polymerization is reached (when a 0.1% solution in benzene at 30 DEG C. has an inherent viscosity of at least 1), the catalyst is destroyed, e.g. by adding water, alcohols or amines, preferably in combination with a solvent for the polymer, and the polymer recovered. The polymers are mainly linear but may contain some branching or cross-linking. They are cured by heating with sulphur at temperatures of 125 DEG C. or more in the presence of vulcanizing accelerators. Normally, 0.1 to 2 parts of sulphur per 100 parts of polymer are required. Compounding agents such as carbon black, clay, silica, esterified silica particles, talc, zinc and magnesium oxides, calcium and magnesium carbonates, titanium dioxide, plasticizers and colouring agents, may be added. They may be used in the preparation of tyres, inner tubes, belts, hose, tubing, wire and cable jackets, footwear, sponges, coated fabrics and other coated and moulded articles. In the Examples: (1), (2) and (3) tetrahydrofuran and 1-allyloxy-2,3-epoxypropane are polymerized together at 0 DEG C. in the presence of antimony pentachloride, and the product is cured; (4) 1-phenoxy-2,3-epoxypropane is added as a third component; (5) the third component is 3,3 - bis - (chloromethyl) oxetane; (6) the mixture consists of tetrahydrofuran, 3,3 - bis - (chloromethyl) oxetane and 3-ethyl-3-allyloxymethyloxetane; (7) to the tetrahydrofuran are added 3,3-diethyloxetane and 3 - ethyl - 3 - allyloxymethyloxetane and the catalyst is phosphorus pentafluoride; (8) 1,2-propylene oxide and 3-ethyl-3-allyloxy-methyloxetane are polymerized with tetrahydrofuran, antimony pentafluoride being added in 1,1,2-trifluorotrichloroethane; (9) the mixture consists of tetrahydrofuran, propylene oxide and p 3-allyloxymethyl-3-methyloxetane, and the catalyst is p-chlorobenzenediazonium hexafluorophosphate; (10) as in (7) except that 3 - methyl - 3 - allyloxymethyloxetane is used instead of the 3-ethyl derivative; (11) 3-methyl-3-(4-pentenyloxymethyl) oxetane is mixed with tetrahydrofuran and 3,3-diethyloxetane; (12) the mixture consists of tetrahydrofuran, diallylmonoepoxide and propylene oxide; (13) the mixture consists of tetrahydrofuran, propylene oxide and 3-allyloxymethyl-3-methyloxetane; (14) ethylene oxide replaces the propylene oxide of (13); (15) the mixture consists of tetrahydrofuran, 3,3 - diethyloxetane and 3 - (4 - methyl - 4 - pentenyloxymethyl) - 3 - methyloxetane. Specification 801,023 is referred to.