CC BY
16
INITIATION OF POLYMERIZATION BY THERMO-ACTIVATED CALCIUM OXIDE
Klyuchnikova Natalya Valentinovna, Belgorod State Technological University. V. G. Shukhov Genov Ivan,
Foundation of Science and Education Bulgaria, Burgas Piskareva Anastasia Olegovna, Belgorod State Technological University. V. G. Shukhov E-mail: a.burdasova@inbox.ru
INITIATION OF POLYMERIZATION BY THERMO-ACTIVATED CALCIUM OXIDE
Abstract: This work is devoted to the verification of using calcium oxide obtained by thermal decomposition from chalk as an initiator and a filler for the copolymer of vinyl benzene and methyl methacrylate. Methods for the obtaining of a highly active form and for the synthesis of a filled copolymer are presented. The decomposition temperature of the obtained filled copolymer is established. (The temperature is significantly higher than the mechanical mixture of polyvinylbenzene and polymethylmethacrylate). The possible copolymerization reaction mechanism is described (from chain initiation to chain development and chain transfer).
Keywords: methacrylate, styrene, calcium oxide, copolymer, free-radical polymerization.
Calcium oxide from ancient times is widely used cium oxide, chalk was used that was decarbonated at
in various industries. One of his first uses was found 600 °C for 4 hours. When the chalk was calcined, its
in construction as a binder. Now it is used in agri- external form and volume did not change. The vol-
culture, medicine, food and chemical industries. It ume that occupied the volatile product, passed into
is also used to remove sulfur dioxide from flue gases the pore volume. The copolymerization reaction was
(in the form ofhydroxide) and in the so-called "self- carried out in a closed laboratory reactor at 60 °C.
heating" dishes [1]. Such widespread use of calcium For the synthesis, 70% of equimolar monomers (vi-
oxide contributes to its availability, low cost and its nyl benzene and methyl methacrylate) and 30% of
specific properties (the ability to absorb water, turn- thermolysis calcium oxide were taken. After mixing
ing into hydroxide, the ability to change its ligands, the components, the formation of a copolymer of
turning into other compounds). vinylbenzene and methyl methacrylate filled with
However, some properties of calcium oxide calcium oxide occurred.
have not yet found such widespread use. It is about In order to determine the structure of the obtained
its ability to initiate polymerization by the radical copolymer, an experiment was carried out on its dis-
mechanism of vinyl monomers [2]. solution in an organic solvent (acetone). A sample
To test the possibility of using thermolysis cal- weighing 5 g was dispersed into powder, mixed with
cium oxide, equimolar mixtures of vinyl benzene acetone in a cylinder with a lapped cap, and stirred
and methyl methacrylate were taken as the initiator for 4 days. About 31% of the copolymer dissolved in
of copolymerization. As a source of thermolysis cal- acetone. It can be assumed that this is a pure copoly-
Section 8. Chemistry
mer not bound to calcium oxide (see reactions 1, 2). The most likely reaction mechanism: The undissolved part was a filled copolymer of vinyl Chain transfer:
benzene and methyl methacrylate (reactions 3, 4) [4].
-[A-(B-A)n-Ca-O-(B-A)n-B]- +A+B ■ -[A-(B-A)n-Ca-0-(B-A)n-B]- + -[A-B]- (1)
-[A-B]- + A + B ■ -[B-A-B-A]- and so on. (2)
Chain origin:
Ca=0 + CH2=C(CH3) C00CH3 ■ -[Ca-0-CH2-C(CH3)]-
I '
C00CH
(3)
3
Ca=0 + CH2=CH(C6H5) ■ -[Ca-0-CH2-CH]-
| (4)
C6H5
In total:
-[Ca-0-CH2-C(CH3)]- + CH2=CH(C6H5) ->-[CH2-CH-Ca-0 -CH2-C (CH3)]-
I I I
C00CH CH C00CH
3 6 5 3
Chain development:
-[B-Ca-0-A]- + A + B ■ - [A-B -Ca-0 -A-B]--[A-B - Ca- 0 -A-B]- + A + B ■ -[B-A-B-Ca-0-A-B-A] - and so on, where A is methyl methacrylate; B is vinylbenzene.
OTA OTG TG
300 373 44&
Temperature °C
Figure 1. Differential-thermal analysis of the obtained copolymer
Temperature The degradation temperatures of range of490-550 K. This increase in the temperature
the resulting filled copolymer were determined by the of destruction is due to the formation of strong chemi-
DTA method. As can be seen (Fig. 1), the destruc- cal bonds between the copolymer and the filler. Esti-
tion begins at 608 K, and ends at 642 oC. The destruc- mated destruction of the copolymer occurs through
tion of the mechanical mixture of unfilled polyvinyl a thermal free radical reaction by the mechanism of
benzene and polymethyl methacrylate occurs in the unfastening or anti-polymerization.
INITIATION OF POLYMERIZATIONBY THERMO-ACTIVATED CALCIUM OXIDE
Using the method of IR spectroscopy to study the obtained copolymer seems to be very useful.
As we can see, the most intense absorption bands of the esters are in the 1732 cm-1 region-the stretching vibrations ofthe carbonyl group C = O. In this region, a series of four absorption bands is observed in the spectrum, which, together with the band at 754 cm-1, are characteristic of the methacrylate structure -CO - O - CH3. Proof of
the presence of the methyl group are the absorption bands at 1388 and 2952 cm-1. The presence of absorption bands of 700 cm-1 indicates the presence of polyvinylbenzene. The absence of a peak at 1645CM-1 is due to the fact that there is no double bond between CC. This all speaks about the presence of PMMA and PS. The absorption bands listed above indicate that the copolymerization was successful [5].
Figure 2. 2 IR-spectrum of the copolymer obtained
Findings: In the work done, the method of using that thermally activated calcium oxide can be used
thermolysis calcium oxide as a filler and at the same as an initiator for the joint polymerization of methyl
time an initiator for methylmetracrylate copolymer methacrylate and styrene. It is established that the
and vinylbenzene was considered. It has been proven obtained copolymer has a high heat resistance.
References:
1. Ershova O. V., Mullina E. R., Chuprova L. V., Mishurina O. A., Bodian L. A. Study of the effect of the composition of the inorganic filler on the physico-chemical properties of the polymer composite material // Fundamental Research. 2014.- No. 12-3.- P. 487-491.
2. Klyuchnikova N. V. The study of the processes of thermolysis of natural calcium carbonates. URL: Per-spektywyrozwojunaukiwewspolczesnymswiecie / - Krakow. 2012.- No. 3.- P. 92-96.
3. Kryzhanovsky V. K. Technical properties of polymeric materials: studies.- right. Manual / V. K. Kryzha-novsky - SPb.: Profession, 2005.- 240 p.
4. Klyuchnikova N. V., Piskareva A. O. Receiving polymer wax from waste production of polyethylene pipes / Bulletin of Belgorod State Technological University. V. G. Shukhov. 2017.- No. 11.- P. 106-109.
5. Klyuchnikova N. V., Gordeev S. A., Gordienko M. D. Polymer composite material based on thermoplastic polyimide / Bulletin of Belgorod State Technological University. V. G. Shukhov. 2017.-No. 12.- P. 126-129.
