DE1298710B - Process for the production of modified copolymers - Google Patents

Description

The invention relates to a process for the production of graft copolymers from styrene polymers and cyclic unsaturated or aromatic compounds, using mixtures of styrene polymers and cyclic unsaturated hydrocarbons and / or aromatic compounds in the presence of catalytic amounts of Friedel-Crafts catalysts subject to oxidizing conditions.

Styrene polymers include polystyrene and copolymers of the To understand styrene, which polymerizes at least 50 percent by weight of styrene contain. Of the copolymers are particularly suitable for the process those made of styrene and other vinyl aromatic compounds or nitriles of Ix, B-unsaturates Carboxylic acids. Suitable vinyl aromatic compounds are, for. B. substituted styrenes, such as nuclear methyl or nuclear halostyrenes or α-methylstyrene, further vinyl anthracene and vinyl carbazole. Possible nitriles of o; "B-unsaturated carboxylic acids are e.g. acrylonitrile or methacrylonitrile.

Cyclic unsaturated hydrocarbons that stand alone or reacted in a mixture with one another or in a mixture with aromatic compounds are, for example, cyclopentadiene, cycloheptatriene, cyclooctadiene (1,3 and 1,5) as well as cyclooctatriene and cyclooctatetraene.

Of the aromatic compounds, in addition to aromatic hydrocarbons, such as benzene, naphthalene, anthracene, also heterocyclic compounds such as thiophene, Quinoline, quinaldine, indole, imidazole, carbazole are possible.

The mixtures of styrene polymers and cyclic unsaturated Hydrocarbons or aromatic compounds expediently contain the same or ten times the amount of cyclic unsaturated hydrocarbons or aromatic Compounds or mixtures of these substances, based on the amount of in the styrene polymers polymerized styrene. However, the connections can also be in a larger one or smaller proportions are reacted with one another.

The conversion to macromolecular products is in the presence of catalytic amounts of Friedel-Crafts catalysts under oxidizing conditions performed.

Aluminum chloride, for example, can be used as Friedel-Crafts catalysts, Aluminum bromide, boron trifluoride and etherate of boron trifluoride and tin (IV) chloride, Zinc (II) chloride and iron (III) chloride are possible. Be under catalytic amounts In the context of this invention, amounts are understood that are substantially below the stoichiometric Quantities lie. The Friedel-Crafts catalysts are generally used in quantities from 0.1 to 10 percent by weight, based on the compounds to be reacted, applied.

Of course, larger amounts can also be used, however this does not generally bring any advantages.

The conversion should be carried out under oxidizing conditions. Oxidizing conditions are present when, in addition to the Friedel-Crafts compound, a further metal compound or mixtures of such metal compounds that are easily reducible are, such as copper (II) -, cobalt (III) -, cerium (IV) -, manganese (III) -, mercury (II) - or Lead (IV) salts, are present.

Oxygen in the air, organic, can also be used as an oxidizing agent or inorganic peroxy compounds genes as well as compounds that are easily oxygenated release, such as manganese dioxide, lead dioxide and potassium nitrate, in question.

The reaction temperatures can be between 30 and 250 "C. They depend not only on the type of connections to be implemented, but also according to the type of Friedel-Crafts compounds and oxidizing agents used and any diluents used. The low temperatures are preferably used when using the cyclic unsaturated hydrocarbons wants to implement, while the use of higher temperatures is expedient in the implementation with aromatic hydrocarbons or heterocyclic aromatic compounds is.

In general, the reaction in the presence of solution and Diluents made, for example of decahydronaphthalene, cyclohexane, Isooctane or n-hexane.

Since the reaction takes place very quickly, it is advisable to use the catalyst and to submit the oxidizing agent and the mixture of styrene polymer and the cyclic unsaturated hydrocarbon or the aromatic compound and after about as much as the implementation takes place, to admit. Depending on the species the compounds used are, if appropriate, advantageously carried out in solution here. It is also possible to use new catalysts and new oxidizing agents in the course of the implementation to feed. You can also make the process continuous by using the new modified copolymers to the extent that they arise from the reaction vessel separates, e.g. B. with the help of a snail. It is beneficial in the presence of Traces of water or alcohol to work.

The new modified copolymers are crystalline and for Partly hard and colored fabrics. They have a metallic sheen and are well known Solvents are often insoluble. Low molecular weight fractions can be washed with Solvents, e.g. B. chloroform or trichlorethylene can be removed. The polymers melt only at relatively high temperatures, which can be over 300 "C. By suitable choice of the reaction components, both in type and however, it is possible to lower the melting points. The new modified Copolymers with low melting points can be used in the one known for thermoplastics Kind, preferably by pressing, are processed into moldings. The higher Melting products are expediently press-sintered.

The polymers are acidified, for. B. by nitric acid or Sulfuric acid, not attacked.

A special feature of the new modified copolymers is their relatively high specific conductivity, which is above 10-12 to 10-5 S / cm or even higher. The products are therefore called semiconductors, coatings and suitable as a thermostable molded body.

The parts mentioned in the examples are parts by weight. The specific Conductivities were measured at 25 "C.

Example 1 100 parts of polystyrene with a K value of 65 (10% strength in cyclohexanone) are dissolved in 100 parts of benzene and the solution slowly at 10 "C to a mixture from 7 parts aluminum chloride and 7 parts copper (II) chloride (anhydrous) given. The reaction mixture is then stirred at 10 ° C. for a further 60 minutes.

A light brown reaction product is formed which is soluble in benzene is, it is separated from the inorganic constituents and polyphenylenes and reprecipitated three times in methanol.

After washing and drying, 123 parts of a new one are modified Copolymer with a K value of 69 (10/0 in cyclohexanone) and a glass transition temperature of 104 ° C obtained.

Example 2 200 parts of a copolymer composed of 70 parts of styrene and 30 parts of acrylonitrile are mixed with 50 parts of benzene and at 180 "C after adding 5 parts of aluminum bromide and 5 parts of ferric chloride for 5 hours heated.

There are 240 parts of an insoluble, crystalline brown-black Product obtained after washing with water and then drying Has a decomposition point above 350 "C. When pressing at 200" C below 200 atm Shaped bodies that have a specific conductivity of 1.9 10-4 S / cm.

Example 3 100 parts of polystyrene with a K value of 42 (1% in cyclohexanone) are mixed with 50 parts of cyclooctadiene (1,3). With stirring at 0 ° C 5 parts of titanium tetrachloride and 5 parts of iron (III) chloride fed and then the mixture heated for 2 hours.

A vigorous reaction produces 137 parts of a reaction product, which is partially soluble. It contains built-in cyclooctadiene components. If you use instead of cyclooctadiene thiophene, 130.5 parts of a reaction product are formed, which is soluble in xylene, toluene and contains built-in thiophene.

Example 4 400 parts of a polystyrene-maleic anhydride copolymer with a K value of 33.5, which contains 50.5 percent by weight of styrene as polymerized units mixed with 100 parts of cyclooctatetraene. With stirring, 10 parts are obtained at 10 ° C Aluminum bromide and 10 parts of iron (III) chloride and 20 parts of benzene were added. Afterward is heated to 100 "C for 5 hours.

It will be after working up and drying 486 parts of a brown colored Obtained reaction product which contains about 50% crystalline components.

The product can be pressed into molded articles.

From a mixture of 90 parts of the reaction product and 10 parts p-Phenylenediamine, molded articles can be obtained which have a specific conductivity of 0.8 10-5 S / cm and are stable up to temperatures of 380 "C.

If you use anthracene instead of cyclooctatetraene and work at a temperature of 205 ° C., 163 parts of a deep black reaction product are obtained obtained after pressing with 10 percent by weight of p-phenylenediamine completely results in insoluble products that have a specific conductivity of 3.6 10-3 S / cm and are stable up to temperatures of 460 "C.

Example 5 100 parts of a 50 percent by weight copolymer Styrene and 50 percent by weight vinyl carbazole with a K value of 63 (0.1% in cyclohexanone-dimethylformamide 1: 1) with 50 parts of cyclopentadiene and 1.5 parts of aluminum bromide at 300 C mixed.

Then air is passed through the reaction mixture for a period of 3 hours directed. The reaction mixture is then heated to 45 ° C. and the mixture further treated with atmospheric oxygen for a period of 3 hours.

There are 147 parts of a new modified copolymer obtained that washed out with cyclohexanone, methanol and then with water and then dried. The modified polymer contains 31.8 percent by weight Cyclopentadiene incorporated and is thermostable up to a temperature of 3500 C.

Example 6 400 parts of a polystyrene-maleic anhydride copolymer has a K value of 33.5, which contains 50.5 percent by weight of styrene as polymerized units mixed with 100 parts of cyclooctatetraene. The mixture is stirred at + 10 ° C 10 parts of aluminum bromide and the amounts of an oxidizing agent given in the table and 20 parts of benzene were added.

The mixture is then heated to 100 ° C. for a period of 5 hours.

After washing and drying, the values given in the table are used Amounts of modified copolymers obtained.

By pressing mixtures of 90 parts of the reaction products and 10 parts of p-phenylenediamine, moldings are obtained whose thermal stability is shown in the table. Oxidizing agent Benzoyl peroxide Barium peroxide Chromium (VI) oxide Amount of oxidant .................... .. 3 parts 5 parts 5 parts Yield of modified copolymers ...... 472 parts 476 parts 493 parts Thermal stability after crosslinking with p-phenylene diamine ........................................ 3800C about 3850C about 4000C

Claims (1)

Claim: Process for the production of modified copolymers from styrene polymers and cyclic unsaturated hydrocarbons or aromatic Compounds denoted by mixtures of Styrene polymers, which contain at least 50 percent by weight of styrene polymerized, and cyclic unsaturated hydrocarbons and / or aromatic compounds at temperatures between -30 and 250 "C in the presence of catalytic amounts of Friedel-Crafts catalysts subject to oxidizing conditions.