SU910712A1 - Process for polymerizing unsaturated fatty acids of vegetable oils or their esters - Google Patents

Description

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The invention relates to methods for the polymerization of unsaturated fatty acids or their esters, vegetable oils in the presence of activated clay catalysts.

Polymerized fatty acids, for example polymerized oleic acid, polymeric acids from vegetable or tall oils, as well as their esters, are widely used commercially as raw materials for polyamide and imidazoline curing agents, plasticizers, hot melt adhesives and for other purposes. Such Polymerized acids are obtained by heating unsaturated fatty acids (hereinafter referred to as NLC) or their esters.

There are two known methods for NLC polymerization - thermal polymerization in the absence of a catalyst and catalytic polymerization. The process of purely thermal polymerization, as a rule, takes place at 2 W-310 ° C and ends after 25–65 h of heating. The advantages of the thermal polymerization process include its simplicity, the absence of catalyst activation stages, the separation of the catalyst from the reaction mass, etc. The disadvantage of this method the temperature is high and the synthesis time is long. In addition, the method of thermal polymerization is

10 is practically unsuitable when using unsaturated fatty acids (and not their esters), since already at 2 ° C 280 ° C, a significant decarboxylation of NLC occurs.

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It is known that, as a catalyst 2 for the process of polymerization of NLC, almost neutral natural clays are most widely used, mainly belonging to montmo rillonites. The use of such catalysts allows reducing the process temperature to 240–280 ° C. Substantially reducing the time. The yield of the target polymer NLC depends on the type of used vegetable oil and can vary from 40-70 by weight of the original NLC. It is known that the majority of natural clays in NLC polymerization processes show insufficient activity and require activation. The process of polymerization of NLC with activated clays can be carried out at 200-2 ° C for 2-8 hours, which is the most technologically acceptable conditions. Various organic or mineral compounds with either basic or acidic properties can be used as activators of natural clays. Compounds such as pyridine, aniline, bis- (aminoaryl) -disulfide, lithium salts, magnesium, etc. are most often used as the main activators. Organic bases are well soluble in polymeric NLCs and when used as activators they contaminate the target products. In this case, special methods of cleaning polymeric NLCs are required, the performance of which dramatically reduces the productivity of the catalytic process as a whole. When natural clays are activated by salts of alkali and alkaline earth metals during the polymerization process of NLC at 230-260 ° С, salts of NLC substances are formed with substances with strong surface-active properties. The presence of such surfactants in the reaction mass prevents the rapid separation of the catalyst and the purification of the desired polymer NLC. As a result, the reduction of the time of the polymerization process due to the use of a catalyst (activated clay) is leveled by the subsequent costs of the stage for breaking up the soaps, coagulating the oleodispersion and removing the catalyst from the reaction mass. Known methods for the activation of clays by acidic compounds, such as hydrochloric acid, tin chloride, and acetic anhydride 1. The clays thus activated are practically non-toxic and much less than the montmorillonites activated by the main agents, contribute to the formation of surfactants during the polymerization process. The disadvantage of such catalysts is the necessity of their preliminary activation, and the activation process of clays is poorly produced and can last up to 3 days. Moreover, in the known methods of polymerization of NLC in the presence of clays activated with acidic agents, surface soaps are still formed. that requires time from 3 to 8 hours for the destruction of oleodispersion, the separation of the catalyst and the purification of the target products. The duration of this additional stage is significantly less than in the case of the use of clays activated with basic agents; nevertheless, carrying out these stages increases the total process time by a factor of 2-3. The closest in technical essence to the invention is a method for the polymerization of unsaturated fatty acids or vegetable oil esters when heated to 180-300 ° C in the presence of a catalytic system based on natural clay activated with acetic anhydride and additionally various salts of lithium 5. The essence of the described known method is next. The clay, preferably montmorillonite, is treated with acetic anhydride at a weight ratio of clay: acetic anhydride of 1: 1. Processing is carried out at boiling acetic anhydride for 3 days. The clay is then filtered, washed several times with benzene and dried to constant weight. The lithium salt added to the reaction mass, such as lithium chloride, fluoride, lithium carbonate or lithium acetate, which is activated in such a way, is additionally added to the reaction mass as a catalyst for the NLC polymerization process. Heating the dispersion of catalysts in NLC or their esters is recommended to be carried out for 4-6 hours at 180-2 ° C, possibly at 300 ° C. The total amount of catalyst injected can range from 5 to 30 by weight of the NLC. With the introduction of 10-25-catalyst NLC polymerization can be carried out at 215 230 ° C, at. This output target NLC fluctuates within 4673 of the mass of the load. The advantages of this method include relatively low temperatures and a rather short time of the catalytic stage of the NLC polymerization process, as well as a good yield of the target products. The disadvantages include the considerable time spent on pre-catalyst activation of the catalyst (natural clay), as well as on the separation of the catalyst from the oleophase and the purification of polymeric NLCs. According to the prototype, the separation of clay from catalysate is carried out at 150 and phosphoric acid is introduced into the reaction mass before filtering (or by fugging) and stirred at 150 ° C for an hour. This technique allows to destroy lithium soaps and coagulate the oleodispersion of clay. oxides and iron salts are removed, resulting in a clarification of the catalyzate. The method described in the prototype for the polymerization of unsaturated fatty acids of vegetable oils or their esters as a whole is inefficient, as it is characterized by considerable time spent on additional operations, such as preactivation of the catalyst, destruction of lithium soaps, destruction of oleodispersion, and separation of the catalyst from the reaction mass, etc. The aim of the invention is to intensify the polymerization process. The goal is achieved by the fact that in the method of polymerization of unsaturated fatty acids of vegetable oils or their esters by heating at 230-300 ° C in the presence of a catalytic system based on natural clay, a catalytic system containing 2-25 May is used as a catalytic system. including natural clay and 0.1 10 May. including dicarboxylic acid, an aliphatic, aromatic or acyclic series or a partial ester of dicarboxylic acid per 100 parts by weight. non-saturated fatty acids (lot. As the dicarboxylic acids of the aliphatic, alicyclic or aromatic series, such as adipic, pimelic, sebacinova, azelaic, lauric, terephthalic, isophthalic, diphenic, tetrahydrophthalic, and terephthalic, terephthalic, isophthalic, diphenoic, tetrahydrophthalic, and terephthalic, terephthalic, isophthalic, diphenoic, tetrahydrophthalic, and terephthalic acids are used. of these acids and glycols or polyols. The catalyst (natural clay) and the activator (dicarboxylic acid) are introduced into the reaction mass simultaneously without preliminary activation of the clay. The amount of the catalyst can fluctuate in Pr eating

lax 2-25% by weight of the original NLC, and the amount of activator is in the range of 0.1-10.

more than in the prototype.

Alcoholysis soyabe Example 1a. th oil. 2 In practice, the polymerization of NLC or their esters in this method is carried out as follows. The vegetable oil is subjected to ethanolysis or hydrolysis, and NLC or their methyl esters are isolated in a known manner. Other NLCs, such as distilled tall oil acids, can be used without pretreatment. In any case, NLC must be cleaned from impurities of glycerol and inorganic compounds. Natural clay and dicarboxylic acid are introduced into the obtained NLC or their esters, while stirring they are allowed to reach 230-300 ° C and incubated for 2-6 hours. The dynamics of the polymerization process are controlled by changing the refractive index of the reaction mass. When a constant refractive index is reached, the reaction is considered complete - further heating does not increase the yield of the target products. The reaction agent (the vessel is cooled to 150-160 ° C and filtered. The catalyst separates easily for 10-30 minutes, depending on the mass of catalyzate. Unreacted acids or their esters, if necessary, are distilled off in vacuum at a residual pressure of 5 iO mm Hg (similarly to known methods). Depending on the type of vegetable oil, the yield of the target polymer NLC can vary from 50 to 80 by weight of the original NLC. Polymer acids (esters) can be obtained from vegetable-derived NLCs, such as flax acid , soybean, sunflower, corn, tung, tall oil, etc. The positive side of the proposed method is its simplicity, the possibility of a short time and a good yield of target products. Compared with the prototype, the proposed method has the advantages that there is no need to pre-activate the catalyst ( natural clay), it is not necessary to neutralize lithium soaps and destroy oleodispersion - in the proposed method, the time spent on the separation of the catalyst from the reaction mixture Enen to a minimum and 5-10 times less than a round-bottom three-neck flask with a capacity of 1 l, equipped with a stirrer, a thermometer and a reflux condenser load 500 g of soybean oil, 1bO g of methanol (5-fold excess in terms of equivalent of neutralization) and 0.5 by weight soybean oil (2.5 g) caustic soda. The reaction mass is heated to boiling methanol and incubated for 12 hours at boiling. To neutralize sodium soda, 4.5 g of 3% hydrochloric acid hydrochloric acid is added, stirred for 10–15 minutes, and settled. The upper oil layer is placed in a Würz flask and approximately 106 g of methanol is stripped off. Semi valuable raw washed twice with 150 ml of cold distilled water and dried over anhydrous sodium sulfate. 425 g (85% of theory) of methyl esters of unsaturated acids of soybean oil are obtained in the form of a light yellow liquid with the following physicochemical indicators: Acid number, mg KOH / G.4-5 Saponification number, mg KOH / G170-182 Iodine number (method Weiss), g JQ.100 g132-140 The refractive index of 1.4545 Example 16. Polymerization of the methyl esters of NLC soybean oil. The resulting 425 grams of fatty acid methyl esters of soybean oil are placed in a 750-ml four-necked flask equipped with a mechanical stirrer, an effective reflux condenser, a thermometer and a bubbler to supply nitrogen under a layer of liquid. To the esters, 25.5 g (6% by weight of the esters) of clay from the Makharadze field and 2.12 g (0.5 by weight of the esters) of adipic acid are added. A nitrogen pad is created and, with stirring, the reaction mass is heated to 240-260 0. The refractive index of the reaction mass is maintained at this temperature for 3 hours, and the refractive index of the reaction mass is monitored every 30 minutes. After 3 h, the refractive index reaches 1.4710. The heating is stopped, since in the future the value of the refractive index remains almost unchanged, and the yield of polymeric NLCs does not increase. The reaction mass is cooled before and filtered. The catalyst is separated from the ole phase for 10 minutes. He9 28 reacted esters (mainly saturated and trans-olefinic acids) are distilled off in vacuum at a temperature of about at a residual pressure of 5–8 mm Hg. Get 225 g (60% by weight of the original NLC) methyl esters of polymeric acids of soybean oil. The product is characterized by the following indicators: Appearance Dark colored viscous liquid with a faint odor of rancid oil Acid number, mg KOH / G 8-10 Saponification number, mg KOH / g 165-178 Iodine number (Method Viissa), g Ja / 100 g 95 -105 Molecular mass (cryoscopy in benzene) 580-620 Refractive index 1.4815 The test experiment of example 1. Soybean may methanolysis pa. Pichig.ka and the selection of methyl esters NLC was carried out according to the method of example 1. The preparation of the catalyst according to the prototype. In a 250 ml flask equipped with a thermometer, mechanical stirrer and reflux condenser with a calcium chloride tube, 50 g of natural clay from the Maharadze site, mainly consisting of montmorillonite with a pH of 8.3, are placed. B2 ml of acetic anhydride was added to the clay and boiled in an oil bath for 3 days. The treated clay was filtered on a Büchner funnel, washed with 2 times 20 ml of benzene and dried in a desiccator over anhydrous sodium sulfate for 6 days until the moisture content according to Fisher 0% EV. 42.5 g of activated clay are obtained. Polymerization of methyl esters of NLC soybean oil. To 412 g of methyl esters of NLC soybean oil are added 41.2 g (10% by weight of esters) of the resulting activated clay and 1.58 g of lithium carbonate. The reaction mass is heated at 2502 oС for 6 h to a constant

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values of the refractive index. Further heating does not lead to an increase in the yield of polymeric NLCs. The result is a stable suspension of clay in the oleophase ..

To coagulate the suspension and clarify the product, 2 g of phosphoric acid is added to the reaction mass, previously cooled to TZO-TbO C, and kept at this temperature and stirring for 3 hours. The treatment of the reaction mass with phosphoric acid is repeated once more, which allows destroy lithium soaps and to some extent lighten catalyzate. After completion of the treatment, the reaction mass is filtered at 150J60 0 and distilled off in vacuum at 190 with a residual pressure of 5–7 mm Hg, unreacted products. As a result, 220, g (53.5% of the mass of the initial ethers) of methyl ethers of polymeric NLC of soybean oil are obtained with the following physicochemical indicators: Acid number, mg KOH / G,. The number of saponis,

mg KOH / G 165-172

Iodine number (Wiiss method),

Mr. g90-106

Molecular weight (cryoscopy in benzene) 550-600 Refractive index 1, 786 Example 2a. Hydrolysis of linseed oil, isolation and purification of fatty acids,

In a four-necked round-bottom flask with a capacity of 2 liters, equipped with a thermometer, a reflux condenser, a mechanical stirrer and an addition funnel, 500 g of linseed oil is loaded and heated to BOC. Then at intense. 300 g of a 302; -aqueous aqueous solution of sodium hydroxide are slowly poured into the stirring. At the end of the addition of all the alkali, the mixture at 80-85 ° C is stirred for k hours. The reaction mixture is cooled to room temperature and neutralized with 165 g of 36% hydrochloric acid. After settling, the organic layer is separated, washed twice with 150 ml of water and dried under vacuum at 80-90 ° C and a residual pressure of 5-tO mi Hg. The result is +00 g (87% of the theoretical)

71210

of flaxed fatty acids of flax oil in the form of a homogeneous light-colored liquid, having the following characteristics:. - Acid number,

mg KOH / H 187-199

The number of saponis,

mg KOH / H19 -199

Iodine number 0 (Wiiss method), g Jii / 100 gIJS-ISB

Example 26. Polymerization of unsaturated fatty acids of flax oil.

5 Polymerization is carried out in the samples of the example 16 kOO g of NLC flax oil in the presence of hQ g of clay from the Crimean field and 2 g (0.5% by weight of NLC) of azelaic acid. The process lasts 2 hours at. After filtering the clay and stripping off unreacted products in vacuum, 289.6 g (72% by weight of the load) of polymeric fatty acids of flax oil are obtained, which are a viscous brown liquid with the following physicochemical indicators:

Acid number,

mg KOH / H178-18

Iodic number

0

r120-128

Molecule Massa 568-582

Refractive index

one,

neither

The control experiment according to example 2 (polymerization of NLC. Of al oil).

Saturated fatty acids and flax oils are prepared and purified as in Example 2a. Clay of the Crimean deposit is activated similarly to cont0.

Rolling. experience of example 1.

Under the conditions of Example 26, 10 g of NLC flax oil will be polymerized in the presence of 1 g (10% by weight of acids) of clay activated with acetic anhydride and 2.7 g (0.0 mg / eq.) Of lithium acetate. At 240-250C, the polymerization process is completed in 5.5-6 hours. Similarly to the control experiment in Example 1, the resulting catalyzate is purified, on-what takes about 5 hours. After the distillation of unreacted monomeric acids is distilled, 297.2 g (72.5% of the mass of the initial fatty acids) polymeric acids of flax oil in the form of a dark-colored viscous liquid with the following physicochemical indicators:

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Acid number,

mg KOH / G175-188

Iodic number

g g10i -113

Molecular weight 570-610

Refractive index, t82i

The conditions and results obtained during the polymerization of the proposed method of other oils are summarized in; tab. 1 and 2.

The technical effect of using the proposed method in comparison with the prototype is shown in the following comparative table. 31071212

Thus, this polymerization method allows to obtain polymeric acids, for example, polymeric acids of vegetable oils with a yield of 505 80% by weight of the original unsaturated fatty acids. The method is technologically simple, fits into the existing process. This eliminates the need for prior activation of the clay catalyst, practically does not form surface-active salts of fatty acids, which simplifies and reduces the time spent on the separation of the catalyst and purification of the final products.

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910712 Table 3

The duration of the process of catalysis, h

The duration of the catalyst activation process

The duration of the process of destruction of olydispersion, neutralization of soap and filtration (separation) of the catalyst, h

Polymer NLC yield,% Synthesis temperature, ° С

Claims (5)

1. US patent number 3732263, cl. 260-407, published. 1973. 2. For the FRG number 211 | 593, CP. From 07 s, publish. 1970. 3. US patent number, class. publish 1970. C. US Patent ff 2,793,220, cl. publish 1957. 5. US Patent No. 3,12039, cl. publish 1968 (prototype)