FR2469402A1 - PROCESS FOR THE PREPARATION OF (ALPHA-ALKYLACRYLATE) -1 TERTIOBUTYL-1 PEROXYETHANES - Google Patents

Abstract

THE INVENTION CONCERNS PROCESSES FOR OBTAINING CHEMICALS. THE PROPOSED PROCESS FOR OBTAINING (ALPHA-ALCOYLACRYLATE) -1 TERTIOBUTYL-1 PEROXYETHANES RESPONDING TO THE FOLLOWING GENERAL FORMULA: (CF DRAWING IN BOPI) IN WHICH R IS CH, CH, CH, CH, AND IS CHARACTERIZED IN THAT 'A TERTIOBUTYL ALPHA-CHLORETHYL PEROXIDE IS REACTED WITH AN UNSATURE ACID IN THE PRESENCE OF TRIETHYLAMINE. THE COMPOUNDS SO OBTAINED CAN BE USED IN PARTICULAR AS COMONOMERS FOR THE PREPARATION OF REACTIONAL COPOLYMERS WITH A VIEW OF THEIR COPOLYMERIZATION WITH VARIOUS VINYL COMPOUNDS.

Description

 The present invention relates to processes for the preparation of chemical compounds and particularly relates to a process for the preparation of new products, (alpha-α-alkylacrylate) -1-tert-butyl-peroxyethanes.

The compounds according to the invention can be used in particular as comonomers for the preparation of reaction copolymers with a view to their copolymerization with various vinyl compounds. Owing to the presence in their structure of peroxide groups, the reaction copolymers can be used for the preparation of graft copolymers. In particular, during the copolymerization of (alpha-alkyl acrylate) -1-tert-butyl-1-peroxyethanes with alkyl acrylates, it is possible to obtain gums which can be used for the synthesis of impact-resistant copolymers or impact-resistant copolymers, based on plastics
ABC characterized by improved weatherability. Furthermore, the peroxide-containing alkyl acrylate gums can be used for the preparation of vulcanized oil and ozone resistant, vulcanization of the gums can be carried out without introduction into the vulcanization agent mixtures.

étant C2H5, C3H7, C4Hg, C5H11. The process which is the subject of the invention for the preparation of said novel compounds has not been described in the literature. The (alpha-alkylacrylate) -tertobutyl-1-peroxyethanes correspond to the following general formula

being C2H5, C3H7, C4Hg, C5H11.

 These novel compounds contain in their structure two reaction groups: a double bond at which it is possible to carry out the copolymerization with various vinyl compounds, and a peroxide group which is capable, at high temperatures, of forming radicals. free.

 (Alpha-alkylacrylate) -1 tert-butyl-1 peroxyethanes are easily soluble liquids dar. aliphatic and aromatic hydrocarbons and their chlorinated derivatives, in single ethers and in esters, in ketones and other organic solvents Depending on the size of the alkyl substituent in alpha position, the density (d4 3 of the compounds according to the invention varies between 0.9311 and 0.9506 g / cm3, while their refractive index (nD20) ranges from 1.4275 to 1.4349.

 The constants of the thermal decomposition of the peroxidic groups of the (alpha-alkyl acrylate) -1 tertiobutyl-1-peroxyethans do not depend substantially on the quantities of the alkyl substituents and, at 1300C, are calculated as 2.0 × 10 -4 to 2.2 × 10 -4 s -1. The size of the alkyl substituent exerts a major influence on the activity, during the polymerization, of the (alpha-alkyl acrylate) -1 tertiobutyl-1-peroxyethanes.If the (alphaalkylacrylate) -1-tert-butyl-1-peroxyethane retains the ability to the polymerization according to a radical mechanism, the compounds having n-propyl, n-butyl, n-amyl substituents in the alpha position show practically no tendency to homopolymerization. However, all the aforementioned compounds are easily copolymerized with various vinyl monomers, their activity is slow compared with the styrene or n-butyl acrylate radicals as the size of the alkyl substituent increases, increasing. Table 1 summarizes the relative activities of alpha-alkyl acrylate-1 tertiobutyl-1 peroxyethanes (rl) in their copolymerization with styrene (relative activity of styrene r 2) or n-butyl acrylate (relative activity of n-butyl acrylate r 3), as well as the values of 1 / r2 and 1 / r3 which characterize the activity of (alphaalcoylacrylate) -1 tertiobutyl-1 peroxyethane relative to the styrene and n-butyl acrylate radicals.

 As shown by the results given in the table, in the case of the copolymerization of (alpha-alkyl acrylate) -1 tertiobutyl-1-peroxyethanes with vinyl monomers there is a marked tendency to alternations of monomer units in the chain of the copolymer that forms.

The final products were identified based on the results of the elemental analysis (C and H), the active oxygen (iodometric) assay and the double bond content (by the method of ozone), determination of the molecular mass (by cryoscopy) and molecular refraction as well as the allocation of the absorption bands of the functional groups in the infrared spectra of the products obtained
#
C = 0 1729 cm -1
# #
C = C 1641 cm-1 I i
C (CH) 1348 cm-1 and 11 @ 8 cm -1
-C (CH3) 3 1248 cm and 1198 cm #
-C - 0 - 1152 cm-1 and 1107 cm-1
# Table 1.

Copolymerization parameters of (alpha-alkyl acrylate) -1 tert-butyl-1 peroxyethanes with styrene and n-butyl acrylate

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The novel compounds, the (α-alkylacrylate) -1-tert-butyl-1-peroxyethanes, objects of the invention, are obtained by reaction between alpha-chlorethyl-tert-butyl peroxide on corresponding unsaturated acids and in the presence of triethylamine according to the following diagram

R being C2H5, C3H7, C4H9 s C5H11,
The synthesis is carried out in the presence of equimolar amounts of the reactants. The process for the preparation of (alpha-alkyl acrylate) -1-tert-butyl-1-peroxyethanes is that it is introduced into a reactor whose temperature is maintained equal to 20 ° -700 ° C. alpha-chlorethyltertiobutyl peroxide and alpha-alkylacrylic acid within petroleum ether.

The triethylamine is added with stirring at such a rate that the temperature in the reactor does not exceed the required value. Brewing is completed after 2 to 3 hours. The precipitated salt is filtered (this salt being triethylamine hydrochloride), the solution is washed with sodium carbonate and water until neutral reaction, it is desiccated in the presence of magnesium sulfate. The solvent is distilled off in vacuo. The target product yield is 90 to 92%.

 Other features and advantages of the invention will be better understood on reading the following description of several concrete but non-limiting embodiments.

 Example 1

 151.5 grams (one mole) of alpha-chloroethyl tert-butyl peroxide and 100 grams (one mole) of alpha-chloroacetyl chloride are placed in a reactor equipped with a stirrer, a thermometer and a dropping funnel. ethylacrylic acid in 1000 cm3 of petroleum ether. The contents of the reactor are brought to a temperature of 300 ° C. and 101 grams (one mole) of triethylamine are then added from the dropping funnel. After 3 hours the solution is filtered, washed with 2% sodium carbonate solution and water, dried in the presence of magnesium sulfate and the solvent is distilled off.

198 grams of (alpha-ethylacrylate) -1 tert-butylperoxyethane are obtained.

 Yield: 92%.

The obtained compound is a clear colorless liquid having the following physicochemical characteristics refractive index () 1.4275 density (d420) 0.9468 g / cm3; Molecular Weight: Found 214
calculated 215; molecular refraction found 58.71;
calculated 58.71; elemental composition,%: found C 60.93; H, 9.44
calculated C 61.07; H, 9.34; active oxygen content: found 7.49%
calculated 7.45%.

base substance content based on the results of the double bond ozone test: 98.9%; characteristic bands in the infrared spectrum (cm-1): 1729, 1641, 1248 and 1198, 1152 and 1107.

 The kinetics of the thermal decomposition of peroxidic groups of (alpha-ethylacrylate) -1-tert-butyl-1-peroxyethane in chlorobenzene have been studied for an initial concentration of the peroxidized compound of 0.05 mol / l according to the results of the invention. iodometric analysis. The kinetics of the decomposition can be put in equation of the first order; it is characterized by the following decomposition constants (in second-1): 1.8.10-5 at 110 C, 7.5.10-5 at 120 C, 2.0.10-4 at 130 C. The half-life period at 1200C is 2.6 hours.

 (Alpha-ethylacrylate) -1-tert-butyl-1-peroxyethane has a weak polymerization activity and can be stored for a long time at room temperature without the formation of polymer. Thus, when keeping the compound without inhibitor at room temperature there is no polymer formation for 20 days.

At elevated temperatures, (alpha-ethylacrylate) -1 tert-butyl-1
peroxyethane in the presence of other radical initiators polymerizes to a
very low speed.

10.0 grams of (alpha-ethylacrylate) -l are placed in an ampoule
tert-butyl-1 peroxyethane and 0.03 gram of azobisiso dinitrile
butyric. The contents of the gas bulb are released by multiple freezing,
by vacuum treatment and subsequent filling of an inert gas (such as
argon). The ampoule is sealed and the reaction is then carried out at 50 ° C. for
2 hours. The polymer which is formed is isolated from the reaction mixture by
precipitation in ethyl alcohol. The isolated polymer is dried at
room temperature under vacuum. Polymer yield: 1.9z.

(1-alpha-ethylacrylate) -1-tert-butyl-1-peroxyethane copolymerizes
easily with vinyl monomers. The copolymerization is carried out
mass with n-butylacrylate in the same way as the homopolymerization of
1 '(alpha-ethylacrylate) -1 tert-butyl-1 peroxyethane, but for reports
different from the monomers and at a temperature of 700C. The constants of
copolymerization were calculated by the method of Tüdes-Kelen.

Test results and calculated copolymerization constants
are shown in Table 2.

 Table 2.

Composition of the copolymer, Composition of the mixture Yield Constants de en
% by moles of monomers,% by moles copolymerized
copoly
30 min. (alpha-ethyl acrylate (30 min. alpha-ethyl acrylate,% acrylate), n-butyl acrylate). by weight tert-butyl-1 (BA) tertiobutyl-1 n-butyl and peroxyethane peroxyethane
(AND) (AND)
36.68 63.32 38.0 62.0 52.3
36.12 63.88 38.0 62.0 54.3 42.17 57.73 46.8 53.2 52.7 0.23-0.07 0.67 ±
0.09
42.08 57.92 46.8 53.2 44.7
46.94 53.06 53.1 46.9 55.6
46.21 53.79 53.1 46.9 41.4
51.27 48.73 57.6 42.4 59.3
52.08 48.92 62.7 37.3 49.4
The product of copolymerization constants of 0.154 indicates the high probability of alternating monomer units in the copolymer ring.

 The copolymerization can be carried out also in emulsion.

 A solution of 1.2 grams of alkylsulfonate in 75 grams is introduced into a quadricol flask equipped with a mechanical stirrer, a reflux condenser, a tube for the introduction of argon and a thermometer. of water and saturates the mixture with argon for 20 minutes. Then introduced a mixture of monomers saturated with argon: 30 grams of butyl acrylate and 4 grams of (alpha-ethylacrylate) -1 tertiobutyl-1 peroxyethane.

After a copolymerization temperature of 250C has been established in the flask, an initiator redox system is introduced therein: 0.032 gram of product known under the trade name "Rongalite", 0.04 gram of product known under the trade name "Trilon B" and 0.02 grams of iron (II) sulfate, dissolved in 5 grams of water, and 0.04 grams of isopropylbenzene hydroperoxide dissolved in 5 grams of water and 0.04 grams of dissolved isopropylbenzene hydroperoxide. in 6 grams of butyl acrylate. The reaction is carried out for 4 hours.

 The copolymer is separated by coagulating the obtained latex by freezing, crushing and washing with water, acetone and ethyl alcohol. The polymer yield is 63% (calculated on the total amount of monomers).

 Example 2

The synthesis was conducted in a manner analogous to that described in Example 1, but instead of alpha-ethylacrylic acid, alpha-propylacrylic acid (112 grams - one mole) was used. 207 grams of (alpha-propylacrylate) -1-tert-butyl-1-peroxyethane of the following formula are obtained:

 Yield: 90%.

The compound obtained is a colorless, clear liquid having the following physicochemical characteristics
refractive index n20 1.4300,
density d420 0.9506 g / cm3;
Molecular Weight: Found 226
calculated 227;
molecular refraction: found 63.25
calculated 63.08
elemental composition,%: found C 62.12 H 9.89;
calculated C 62.48 H 9.63;
active oxygen content,%: found 7.18
calculated 7.05;
base substance content according to the determination of the double bonds to ozone: 98,6%; characteristic bands of the infra-red spectrum, cm @: 1729, 1640, 1248 and 1198, 1152 and 1107.

 The kinetics of the thermal decomposition of (alphapropylacrylate) -1-tert-butyl-1-peroxyethane were studied in a manner analogous to that of Example 1. Decomposition constants (second): 1.9.10 at 110 ° C., 6.9.10 -5 to 120 ° C., 2.0 × 10 -4 to 130 ° C. Half-life period at 120 ° C.: 2.8 hours.

 The polymerization is carried out in a manner analogous to that of Example 1, in place of 1 '(alpha-ethylacrylate) -1-tert-butyl-1-peroxyethane and 1' (alpha-propylacrylate) -1-tert-butyl-1-peroxyethane.

 When retaining (alpha-propylacrylate) -1-tert-butyl-1-peroxyethane at room temperature for 20 days, no polymer is formed.

 If the polymerization is carried out at 800 ° C. in the presence of azobisisobutyric acid dinitrile, no polymer formation is observed either.

 The copolymerization is carried out in a manner analogous to that of Example 1 using instead of (alpha-ethylacrylate) -1-tert-butyl-1-peroxyethane I '(alpha-propylacrylate) -1-tert-butyl-1-peroxyethane, and at instead of n-butyl acrylate, styrene.

 The experimental results and calculated copolymerization constants are shown in Table 3.

Table 3
Composition of the Composition Composition of the Polymer, Yield in Constants of Monomers @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
calculated by copolymerization
relative to the amount set blankcompress on (alpha-pro- Styrene (alpha-pro Styrene rPT pylacryla- (St) pylacrylamonomer total rs) -l ter- te) -l teren 90 min, tiobutyl-1 tiobutyl-1
% by weight peroxy-peroxyethane ethane
(PT)
5.0 95.0 2.0 98.0 20.1
15.0 85> 0 7.2 92.8 16.4
25.0 75.0 12.9 87.1 14.3 0.0 + 0.1 0.75- # 0.10
50.0 50.0 22.1 77.9 10.0
The product of the copolymerization constants is zero, which
shows that there are alternations of monomer motifs in the channe of
copolymer.

The bulk copolymerization is carried out in a manner analogous to that which
was described in Example 1, using instead of (alpha-ethylacrylamide)
tert -butyl-1-peroxyethane (alpha-propylacrylate) -tertobutyl-1
peroxyéthane. Experimental results and calculated constants of
copolymerization are shown in Table 4.

Table 4
Composition of the copolymer, Composition of the mixture Yield Constants of
in
% moles of monomers,% moles copolymerization
copolymer
in 30 minutes, (alpha-propyl-acrylate from (alpha-pro-acrylate
% by weight rPT rBA
acrylate) -1-n-butyl pylacry-de-tertlobutyl-1 (BA) late) -1-n-butyl peroxyethane tert-butyl
(PT) 1 peroxy
ethane
l 2 3 4 5 6
25.64 74.36 23.2 76.8 46.7
27.16 72.84 23.2 76.8 49.3
36.58 63.42 37.7 62.3 68.5
Table 4 (continued)
1 2 3 4 5 6 39.86 60.14 37.7 62.3 64.5 0.028+ 0.50- 38.03 61.97 39.2 60.8 55.0 0.005 0.05 37.40 62 , 60 39.2 60.8 64.3 52.77 47.23 56.3 43.7 76.2 49.85 50.15 56.3 43.7 73.1
The product of copolymerization constants of 0.014 is indicative of the high probability of alternating monomer units in the chain of
copolymer.

 Example 3

The synthesis is conducted in a manner analogous to that described in
Example 1, using instead of alpha-ethylacrylic acid
alpha-butylacrylic (124 grams -one mole). 220 grams of (alpha-butylacrylate) -1-tert-butyl-1-peroxyethane are obtained, corresponding to the formula
next

 Yield: 90%.

The compound obtained is a colorless, clear liquid having the following physicochemical characteristics
refractive index nD20 1.4334;
density d4, 9394 g / cm
Molecular Weight: Found 232
calculated 239;
molecular refraction: found 67.62,
calculated 67.73;
elemental composition,%: found C 64.05 H 9.80,
calculated C 63.89 H 9.92;
active oxygen content,%: found 6.83
calculated 6.70;
base substance content based on duplicate dosage results
ozone bonds: 98.8%;
Characteristic bands of the infrared spectrum, cm-1: 1730, 1638, 1246 and
1198, 1150 and 1108.

The kinetics of the thermal decomposition of (alpha
butylacrylate) -1 tertiobutyl-1 peroxyethane in a manner similar to that
of example 1. The decomposition constants (in seconds) are the
following amounts: 2.6 × 10 -5 at 110 ° C., 5.8 × 10 -5 at 120 ° C., 2.1 × 10 -4 at 1300 ° C. The period
half-life at 1200C is 3.3 hours.

The polymerization is carried out in a manner similar to that described in
Example 1, using instead of (alpha-ethylacrylate) -1 tertiobutyl-1
peroxethane 1 '(alpha-butyl-acrylate) -1-tert-butyl-1-peroxyethane.

Polymer formation was not observed at room temperature,
or at a temperature of 800 ° C., in the presence of azobisisobutyric acid dinitrile.

Bulk copolymerization is carried out in an anological manner to that
of Example 1, using instead of (alpha-ethylacrylate) -1 tertiobutyl
-1 peroxyethane (alpha-butyl-acrylate) -1 tertiobutyl-1 peroxyethane
experimental results and copolymerization constants are indicated
in Table 5.

Table 5
Composition of the copolymer, Composition of the mixture Yield Constants of
in
% by mole of monomers,% by copoly-copolymerization
mother moles, in
30 sec. %
rr
by weight BT BA (alpha-butyl acrylate of (alpha-bu- acrylate acrylate) -l n-butyl tyl-acry- tert-butyl-1 (BA) late) -l n-butyl peroxyethane tertio
(BT) butyl-l
peroxy
ethane
28.28 71.71 18.9 81.1 41.7
37.46 69.54 27.8 72.2 33.3
38.77 61.23 37.1 62.9 42.3 0.35 ± 0.27+
49.94 50.06 49.8 50.2 59.9 0.003 0.09
47.13 52.87 55.3 44.7 59.7
30.76 69.24 55.3 44.7 52.7
The product of copolymerization constants of 0.009 indicates a high probability of alternating monomer units in the copolymer chain.

 Example 4

The synthesis was conducted in a manner analogous to that of Example 1, using alpha-amylacrylic acid (136 grams - one mole) instead of alpha-ethylacrylic acid. 238 grams of (alpha-amyl acrylate) -1 tertiobutyl-1 peroxyethane are obtained, corresponding to the following formula

 Yield: 92%.

The compound obtained is a colorless, clear liquid with the following physicochemical characteristics
refractive index nd20 1.14349;
density d420 0.9311 g / cm3;
Molecular Weight: Found 243
calculated 251;
molecular refraction: found 72.34
calculated 72.38;
elemental composition,%: found C 65.47 H 10.14
calculated C 65.30 H 10.21;
active oxygen content,%: found 6.19
calculated 6.36;
base substance content based on the results of the determination of the double bonds to ozone: 99,1%;
-1 characteristic bands of the infrared spectrum, cm: 1728, 1638, 1245 and 1194, 1150 and 1107.

 The kinetics of the thermal decomposition of (alpha-amylacrylate) -1-tert-butyl-1-peroxyethane have been studied in a manner analogous to that of Example 1. The constants of the decomposition (in seconds 1) are 2.1 × 10-5. at 110 ° C., 8.1 × 10 -5 at 120 ° C., 2.2 × 10 -4 at 130 ° C. Half-life period at 1200 ° C.: 2.4 hours.

 The polymerization was conducted in a manner analogous to that described in Example 1, using instead of (alpha-ethylacrylate) -1-tert-butyl-1-peroxyethane (alpha-amylacrylate) -1-tert-butyl-1-peroxyethane.

Neither at room temperature nor at 800C in the presence
of azobisisobutyric acid dinitrile, we observed
polymer
The copolymerization is conducted in a manner similar to that which has been
described in Example 1, using instead of (alpha-ethylacrylate) -l
tert-butyl-1-peroxyethane (alpha-amylacrylate) -1-tert-butyl-1
peroxethane, and instead of n-butyl acrylate, styrene.

Experimental results and calculated copolymer constants
are shown in Table 6.

Table 6
Composition of the blend Composition of the copolymer, Yield Co-monomer copode constant,% mole% copolymerization
lymère
moles compared to the
rST rST (alpha-amyl-styrene (alpha-amyl-styrene global acrylate) -l S) acrylate) -l monotertiobutyl-1 tertiobutyl-1 peroxyethane peroxethane mothers 120 minu
(AT),%
in weight
5 95 6.0 94.0 25.0
15 35 10.5 89.5 24.0 0.0 # 0.1 0.36 # 0.10
25 75 16.6 83.4 20.6
50 50 25.8 74.2 7.0
The product of the copolymerization constants is equal to zero, as evidenced by the alternation of the monomer units in the copolymer chain.

 The copolymerization is carried out in bulk analogously to that described in Example 1, using instead of (alpha-ethylacrylate) -1-tert-butyl-1-peroxyethane (alpha-amylacrylate) -l tertiobutyl-1 peroxyethene.

The experimental results and calculated copolymerization constants are collated in Table 7.

 Table 7.

Composition of the copolymers, Composition of the mixture Yield Constants of
in copoly-copolymerization
% by moles of monomers,% by mother
moles 30 minu
your,%
by weight rAT rBA (α-amyl acrylate of (alpha-amyl acrylate acrylate) -1 n-butyl acrylate) -1 tert-butyl-1 (BA) tert-butyl-1 n-butyl peroxyethane peroxyethane
(AT)
25.9 74.1 13.8 86.2 39.7
37.3 62.7 35.7 64.3 53.4
37.8 62.2 35.7 64.3 54.8
46.7 53.3 48.7 51.6 56.5 0.11 0.05
48.8 51.2 48.4 51.6 66.2
44.8 55.2 51.7 48.3 54.0
54.9 45.1 51.7 48.3 55.1
The product of copolymerization constants of 0.019 is indicative of the high probability of alternating monomer units in the copolymer chain.

 The (alpha-alkyl acrylates) -1-tert-butyl-1-peroxyethanes have, depending on the size of the alkyl substituent at the alpha position, a varied activity in the copolymerization with vinyl compounds. This property makes it possible to obtain reaction copolymers with adjustable distribution of the peroxide groups along the chain of the macromolecule. The reaction copolymers in question can be used for the preparation of graft copolymers having the desired distribution of grafted alumina. The almost total absence of the ability of (alpha-alkyl acrylates) -1-tert-butyl peroxyethanes to homopolymerization leads to production of solubilized peroxidic monomer unit distribution copolymers, which makes it possible to achieve a higher priming efficiency in the synthesis of the graft copolymers than in the case of using the known methacrylate-1-tert-butyl-1-peroxyethane (application author's certificate in the USSR n02492991 / 23-5 / 075443).

 The use of (alpha-alkylacrylate) -1-tert-butyl-1-peroxyethanes makes it possible to improve the technology for the preparation of reaction copolymers. Due to their low activity in the polymerization of the above-mentioned peroxidic monomers, it is possible to reduce the overall copolymerization rate and to reduce the heat evolution in the process, which makes it possible to better preserve the integrity of the peroxide groups in the copolymer obtained.

 The (α-alkylacrylate) -1-tert-butyl-1-peroxyethanes, against known permonomers, can be stored and transported without polymer formation in the absence of polymerization inhibitors. The possibility of preserving the compounds according to the invention under ordinary conditions, without the introduction of inhibitors, makes it possible to use the peroxidized monomers according to the invention without prior purification and to avoid their losses in the operations related to the elimination of inhibitor.

 Of course, the invention is not limited to the embodiments described and shown which have been given by way of example.

In particular, it comprises all the means constituting technical equivalents of the means described and their combinations, if they are executed according to its spirit and implemented in the context of the following claims.

Claims (3)

 A process for the preparation of (alpha-alkyl acrylate) -1 tertiobutyl-1 peroxyethanes corresponding to the following general formula

 wherein R is G2H5, C3H7, C4H9, C5H11 characterized in that an alpha-chlorethyl tert-butyl peroxide is reacted with an unsaturated acid in the presence of triethylamine.  2. Process according to claim 1, characterized in that as unsaturated acid is used a compound corresponding to the following general formula

 wherein R is C2H5, C3H7, C4H9, C5H11  3. Novel compounds, characterized in that they consist of (alpha-alkylacrylate) -tertobutyl-1-peroxyethanes corresponding to the general formula:

 wherein R is C2H5, C3H7, C4H9, C5H11