GB731720A - Olefinic ether-ester nitriles and polymers thereof - Google Patents

Abstract

The invention comprises as new products ether-ester nitriles having the general formula <FORM:0731720/IV (a)/1> in which Y, R, R1, R11 and R111 are hydrogen atoms or methyl groups and n is 1, 2 or 3 (see Group IV (b)), and polymers thereof. Specified monomers are 2-(21-cyanoethoxy) ethyl acrylate and methacrylate, 2-(21-cyanopropoxy) ethyl acrylate and methacrylate, 2-[21-(211-cyanoethoxy) ethoxy] ethyl acrylate and methacrylate and 2-(21-cyanoethoxy)-1-methylethyl acrylate and methacrylate. The polymers are preferably obtained by aqueous emulsion polymerization of the monomers in the presence of a water-soluble peroxy compound and preferably also of a wetting or emulsifying agent. Specified water-soluble peroxy compounds are sodium peroxide, hydrogen peroxide, sodium perborate, the sodium salts of other peroxy acids, and the potassium, ammonium and other water-soluble salts of peroxy acids. Specified wetting or emulsifying agents are the water-soluble salts of fatty acids, e.g. sodium oleate, potassium stearate, mixtures of water-soluble fatty acid salts such as the soaps prepared by the saponification of animal and vegetable oils, the amino soaps such as the triethanolamine and dodecylmethylamine salts of rosin acids and mixtures thereof, the water-soluble salts of half esters of sulphuric acid and longchain alkyl alcohols, and sulphonated hydrocarbons, e.g. alkylaryl sulphonates. The emulsion polymerization is generally conducted at 20-100 DEG C. and preferably between 40 DEG and 60 DEG C. The preferred manner of operation involves heating the water containing a small amount of catalyst and wetting-agent to the ultimate polymerization temperature and then introducing a stream of mixed monomer and catalyst. The polymeric products are rubbery and may be compounded with fillers such as carbon black and zinc oxide, vulcanization agents such as sulphur and vulcanization accelerators. An example is given of the aqueous emulsion polymerization of 2-(21-cyanoethoxy) ethyl acrylate using potassium persulphate as catalyst, the product being a soft rubbery polymer. In another example the product of the above example is compounded on cold rolls with zinc oxide and carbon black and small amounts of sulphur, mercaptobenzthiazole, stearic acid, and tetramethylthiuram disulphide and the compounded mixture is vulcanized at 500 p.s.i. at 298 DEG C. for 4 hours to yield a vulcanizate which is stated to be insoluble in standard solvents such as carbon tetrachloride, hexane, gasoline and hydrocarbon oils. Reference is also made to the polymer of 2-(21-cyanopropoxy) ethyl acrylate.ALSO:The invention comprises as new compounds olefinic ether-ester nitriles having the formula <FORM:0731720/IV (b)/1> in which Y, R, R1, R11 and R111 are hydrogen atoms or methyl groups and n is 1, 2 or 3, and polymers thereof. The compounds may be obtained by treating, in the presence of an esterification catalyst, acrylic acid or methacrylic acid or an acid halide thereof such as acrylyl chloride or methacrylyl bromide, or an anhydride thereof, with a hydroxyalkoxy nitrile of the general formula <FORM:0731720/IV (b)/2> in which R, R1, R11 and R111 and n are as defined above. They may also be obtained by ester interchange, e.g. by reacting an alkyl acrylate with an ester such as a cyanoalkoxyalkyl acetate. Specified esterification catalysts are organic or inorganic acids or basic materials, e.g. sulphuric, hydrochloric, or benzenesulphonic acid, potassium hydroxide, sodium acetate or sodium methoxide. The condensation is preferably effected in the presence of a polymerization inhibitor, e.g. pyrogallol, hydroquinone, diphenylamine or methylene blue and it is also an advantage to include in the reaction mixture a liquid such as toluene or xylene which forms an azeotrope with water. Examples describe the production, by the direct esterification method, of (1) 2-(21-cyanoethoxy) ethyl acrylate from 2-(21-hydroxyethoxy)propionitrile [prepared from ethylene glycol and acrylonitrile in the presence of a basic catalyst] and acrylic acid in the presence of toluene, and a small amount of pyrogallol and benzene sulphonic acid; (2) 2-(21-cyanopropoxy)ethyl acrylate from 2 - (21 - hydroxyethoxy) - 1 - methylpropionitrile (prepared from ethylene glycol and methacrylonitrile in the presence of a basic catalyst) and glacial acrylic acid (containing a trace of methylene blue) in the presence of toluene, pyrogallol, cupric chloride and benzene-sulphonic acid; (3) 2-[21-(211-cyanoethoxy) ethoxy] ethyl acrylate from 2-[21-(211-hydroxyethoxy)ethoxy]propionitrile (prepared from diethylene glycol and acrylonitrile in the presence of choline) and glacial acrylic acid as in (2); (4) 2 - (21 - cyanoethoxy) - 1 - methylethyl acrylate from 2-(21-hydroxypropoxy)propionitrile (prepared from propylene glycol and acrylonitrile in the presence of a basic catalyst) and glacial acrylic acid as in (2). Other hydroxyalkoxy nitriles which may be used are 2-(21-hydroxy-11-methylpropoxy)propionitrile obtainable from 2,3-butylene glycol and acrylonitrile, and the hydroxy polyalkoxyalkylene nitriles obtainable by reaction of such polyglycols as triethylene glycol or tripropylene glycol with acrylonitrile or methacrylonitrile. Other ester products mentioned are the methacrylates derived from the hydroxyalkoxy nitriles used in the examples. The products may be polymerized to form rubbery products (see Group IV (a)). The hydroxy-alkoxy nitriles used as starting materials are obtainable by the addition of acrylonitrile or methacrylonitrile to alkylene glycols or polyalkylene glycols having the formula <FORM:0731720/IV (b)/3> in which X is 0, 1 or 2.