| 摘要 |
Cation exchange resins are prepared by proliferously copolymerizing at least 70 per cent of acrylic acid or an ester thereof with up to 30 per cent of a polyolefinic organic compound and, when using the ester, saponifying to obtain a popcorn copolymer containing at least 70 per cent of acrylic acid. The polymerization may be effected in bulk, solution or suspension and up to 0.5 per cent of a peroxide catalyst such as benzoyl, lauryl or stearoyl peroxide, t-butyl hydroperoxide or inorganic per-salts may be used. The copolymerization is carried out at a temperature of 20 DEG to 80 DEG C., in the substantial absence of oxygen, such as in an inert atmosphere, and in the presence of a seed of a similar or dissimilar proliferous copolymer. Acrylic acid esters specified are the methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, t-butyl, iso-amyl, cyclohexyl, octyl, lauryl, octadecyl, benzyl and phenylethyl esters. Polyolefinic compounds which act as popping agents are divinyl benzene, butadiene, isoprene, bimethallyl, biallyl, trivinylbenzene, dicyclopentadiene, dimethallyl ether and sulphide, vinyl allyl ether, diallyl maleate and 2-chloroallyl crotonate. Saponification is effected by aqueous or alcoholic bases such as sodium, potassium and quaternary ammonium hydroxides. Sodium salts may be converted to potassium salts by means of excess potassium salts and the sodium or potassium salts may be converted to acid resins with hydrochloric or sulphuric acid. The products are insoluble in solvents which dissolve the normal copolymers. They swell in water to form gelatinous suspensions suitable for use in sodium reduction therapy.ALSO:A therapeutic composition for the treatment of edema consists of an impalpable dispersion in an aqueous medium of an opaque, infusible, proliferous copolymer of (a) acrylic acid and (b) a polyolefinic organic compound in which the olefinic linkages are in the aliphatic portion of the molecule, said copolymer containing at least 70 per cent. proliferously copolymerized acrylic acid (see Group IV (a)) and being capable of exchanging cations. p |
