GB746914A - Olefinic ether-ester nitriles and polymers thereof - Google Patents

Abstract

4 - (21 - Cyanoethoxy) butyl acrylate and 3-(21-cyanoethoxy) propyl acrylate (see Group IV (b)) may be polymerized or copolymerized with monomeric compounds containing the vinyl group, e.g. vinyl chloride, styrene or acrylonitrile. The homopolymers are soft, rubbery products which may be compounded with well-known rubber fillers such as carbon black and zinc oxide, vulcanization agents such as sulphur, para-quinone dioxime, polymeric paradinitrosobenzene, in the presence or absence of vulcanization adjuvants, to give vulcanized rubber having solvent-resistant properties and temperature flexibility. The polymers may be prepared by mass, solution, or emulsion polymerization. In the latter method which is preferred the monomer with or without an olefinic comonomer containing a vinyl group is emulsified in the presence of water containing a suitable peroxy catalyst and preferably an emulsifying agent. All the monomer may be charged to the polymerization reactor at the beginning of the reaction or it may be added periodically during the course of the reaction. The emulsifying agent may be introduced either at the start or in increments during the reaction. Specified catalysts are sodium peroxide, hydrogen peroxide, sodium perborate, the sodium salts of other peroxy acids or potassium, ammonium or other water-soluble compounds containing a peroxy group. Specified emulsifying agents are the water-soluble salts of fatty acids such as sodium oleate and potassium stearate, mixtures of water-soluble fatty acid salts such as the common 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 the half esters of sulphuric acid and long-chain alkanols and sulphonated hydrocarbons such as alkylarylsulphonates. The emulsion polymerization is generally conducted at 20-100 DEG C. and preferably between 40 DEG and 60 DEG C. The vulcanization may be carried out on cold rolls with a vulcanizing agent such as sulphur in the presence of conventional vulcanizing adjuvants, and fillers such as carbon black, clay and zinc oxide. An example is given of the aqueous emulsion polymerization of 4-(21-cyano-ethoxy) butyl acrylate using potassium persulphate as catalyst and examples are also given for the vulcanization of the product in the presence of various adjuvants and fillers.ALSO:The invention comprises as new compounds 4 - (21 - cyanoethoxy) butyl acrylate and 3-(21-cyanoethoxy) propyl acrylate. They may be prepared by treating a hydroxy alkoxy nitrile having the formula HO.CH2(CH2)nCH2OCH2CH2CN in which n is 1 or 2 with acrylic acid, acrylic acid anhydride, or an acrylic acid halide, in the presence of an esterification catalyst. The esterification is preferably carried out in the presence of a polymerization inhibitor and of a liquid, such as benzene or toluene, which forms an azeotrope with the water liberated when acrylic acid or its anhydride is employed. The esters may also be prepared by ester interchange, e.g. by reaction of a suitable alkyl acrylate with a suitable cyanoalkoxyalkyl ester such as 4-(21-cyanoethoxy) butyl acetate. Specified esterification catalysts are organic or inorganic acids or basic materials, e.g. sulphuric, hydrochloric and benzene sulphonic acids, potassium hydroxide, sodium acetate, sodium methoxide, pyridine or other organic tertiary base. In an example 4-(21-cyanoethoxy)-1-butanol is first prepared by adding acrylonitrile to a mixture of 1,4-butylene glycol and choline and fractionating the product under reduced pressure and is then esterified by refluxing it with glacial acrylic acid in the presence of toluene as entraining agent, benzenesulphonic acid and pyrogallol to yield 4-(21-cyanoethoxy) butyl acrylate. In a similar manner 3-(21-cyanoethoxy)-1-propanol is prepared from acrylonitrile and 1,3-propylene glycol in the presence of choline and is then esterified with glacial acrylic acid in the same way. The products may be polymerized to yield soft rubbery products (see Group IV (a)).