DE699445C - Process for the polymerization of fumaric acid esters - Google Patents

Description

Process for the polymerization of fumaric acid esters It is known that one with hours. Heating of fumaric acid diethyl or methyl ester in Presence of. Benzoyl peroxide gives a soft, sticky resin. With -Application higher temperatures up to. The polymers are somewhat boiling point of the esters more solid, but still remain strongly adhesive and are more or less liquid.

It has now been found that solid, non-adhesive polymers of Fumaric acid esters are obtained when they are used in the presence of small amounts of oxygen-releasing agents Substances polymerized in aqueous dispersion in a closed vessel. Strangely enough can not be this polymerization in the. carry out an open vessel, as this is the case at all no polymerization occurs.

To achieve the most stable possible dispersion of the fumaric acid esters In water it is advisable to use capillary-active substances, especially those that have a lipoid and its hydrophilic residue have to be mitzuverKTenden. Suitable substances of this type are, for example, alkylated naphthalenesulfonic acids, sulfuric acid esters.or Sulphonic acids of higher fatty alcohols, additive compounds of one or more Molecules of ethylene oxide on hydroxyl or amino groups containing, long-chain organic Compounds as well as the taurides of higher fatty acids or sulfated Fettsäumamides.

Suitable polymerization-promoting, oxygen-releasing substances are for example inorganic or organic P.ero2tyde, peracids and their salts, z. B. hydrogen peroxide, benzoyl peroxide, acetoperacid, potassium or ammonium persulfate.

The polymerization generally begins at temperatures above 50 °. The dispersion is expediently adjusted to pH 5 to 7. Minor additives, e.g. B. up to about 5%, of substances that polymerize easily, such as butadiene, acrylonitrile or vinyl chloride, cause an acceleration of the polymerization d Fumaric acid ester. @ ': " The polymers obtained are b "' ders high molecular weight and have in the G @@ = ';' In addition to the polymerization obtainable by block polymerization, it has a considerable strength.

Example i 500 parts of diethyl fumarate are added with 6 parts of potassium persulfate and 15 parts of hydrogen peroxide in 1 500 parts of one 2% aqueous solution of u-oxyoctodeca.nsulfonsaurem sodium emulsified. Then it will be with good stirring for about 48 hours in a closed vessel to 75 bis 8o ° heated. A yield of more than 90% of theory is obtained with an ordinary Temperature-stable, plastic, stretchable polymer.

EXAMPLE 2 In 22oo parts of a 2% aqueous solution of a-oxyoctodecanesulfonic acid sodium, which contains i 5 parts of potassium persulfate, 35 parts of hydrogen peroxide and 3 5 parts of secondary sodium phosphate, are c closed vessel 50 parts fumaric acid #thylester suspended. Then 2 Atrn. Press on the cloth, and the whole thing will work Heated for 72 hours at 95 ° with thorough stirring. By adding electrolytes, the resulting polymerizate can be deposited as a granular powder. It can be masticated on warm rollers and can be used for the production of elastic fittings, eg. B. Seals, serve.

In the same way, a mixture of 250 parts of diethyl fumarate can be used and polymerize 250 parts of dimethyl fumarate * or dibutyl fumarate.

Claims (1)

PATENT CLAIM: Process for the polymerization of fumaric acid esters, characterized in that .these in the presence of oxygen-releasing substances polymerized in aqueous dispersion in a closed vessel.