Research in the Chemistry of Carbazole Derivatives
Abstract Generated abstract
The study examines the formal kinetics of radical polymerization of 9-(2-hydroxyethyl)carbazole methacrylate in benzene solution using azobisisobutyric acid dinitrile as initiator. Polymerizations were carried out in sealed ampoules under varied monomer and initiator concentrations and temperatures, with polymer yields used to determine initial rates and graphical rate orders. The polymer yield increased with reaction time, and analysis indicated first-order dependence on monomer concentration and half-order dependence on initiator concentration. Temperature dependence followed an Arrhenius-type relationship, giving an activation energy of 19 ± 0.5 kcal/mol.
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PROCEEDINGS
OF THE TOMSK POLYTECHNIC INSTITUTE NAMED AFTER S. M. KIROV,
ORDER OF THE OCTOBER REVOLUTION AND ORDER OF THE RED BANNER OF LABOR
Volume 257 1973
RESEARCH IN THE CHEMISTRY OF CARBAZOLE DERIVATIVES
97. Kinetics of the Radical Polymerization of 9-(2-Hydroxyethyl)carbazole Methacrylate in Solution
V. P. Lopatinskii, I. P. Zherebtsov, V. M. Sutyagin,
V. M. Amosova
(Presented by the scientific-methodological seminar of the organic departments and laboratories of TPI)
The literature contains information on the preparation of a polymer based on 9-(2-hydroxyethyl)carbazole methacrylate in the presence of Ziegler–Natta catalysts. However, information on the kinetics of the radical polymerization of the indicated monomer is lacking. In order to study it, we investigated the polymerization of 9-(2-hydroxyethyl)carbazole methacrylate in benzene solution under the action of dinitrile of azobis(isobutyric acid), DAIC.
The reaction was carried out in ampoules, which, after loading with the required amount of monomer, initiator, and solvent and after threefold evacuation, were sealed. 9-(2-Hydroxyethyl)carbazole methacrylate was prepared according to the procedure [1], with \(T_{\mathrm{m}} = 79^\circ\). Before use, DAIC was twice reprecipitated from ethanol and dried in vacuum at \(20^\circ\). Benzene was purified by a known procedure [2], having constants coinciding with the literature values. After opening the ampoules, the polymers obtained were precipitated with ethanol; the precipitate was transferred onto preweighed filters, washed with hot precipitant, dried at \(20^\circ\) in a vacuum oven to constant weight, and the yield was determined. The polymerization rate was determined from the slope of the straight line expressing the dependence of the amount of polymer on time.
Table I presents experimental data on the polymerization of the indicated monomer in benzene solution at \(55^\circ\).
From Table 1 it is evident that the polymer yield increases with increasing duration of the process and represents a directly proportional dependence of the reaction rate on time.
From the initial polymerization rates, the reaction orders were calculated by the graphical method [3] from the logarithmic dependence of the polymerization rate on the concentrations of the monomer and initiator; these proved to be 1.0 and 0.5, respectively.
Table 1
Polymerization of 9-(2-oxyethyl)carbazole methacrylate in benzene solution at 55°
| Initiator concentration, mole/l · 10³ | Monomer concentration, mole/l | Polymerization duration, min | Polymer yield, % | Polymerization rate, mole·l⁻¹·sec⁻¹ · 10⁵ |
|---|---|---|---|---|
| 1.14 | 0.78 | 3 | 7.00 | 29.00 |
| 1.14 | 0.78 | 6 | 14.00 | 29.00 |
| 1.14 | 0.78 | 9 | 18.00 | 29.00 |
| 1.14 | 0.78 | 12 | 26.00 | 29.00 |
| 9.15 | 0.39 | 5 | 9.00 | 1.20 |
| 9.15 | 0.78 | 5 | 11.20 | 3.10 |
| 9.15 | 1.20 | 5 | 11.50 | 4.50 |
| 9.15 | 1.56 | 5 | 12.00 | 6.40 |
| 0.90 | 0.78 | 5 | 3.80 | 1.00 |
| 3.60 | 0.78 | 5 | 9.60 | 2.50 |
| 6.40 | 0.78 | 5 | 15.10 | 3.40 |
| 11.00 | 0.78 | 5 | 19.60 | 4.75 |
The influence of temperature on this process showed that, for the polymerization of 9-(2-oxyethyl)carbazole methacrylate, the dependence of the logarithm of the reaction rate on the reciprocal absolute temperature is well fulfilled. The experimental data, processed by the method of mathematical statistics, made it possible to calculate the activation energy, whose numerical value is equal to 19 ± 0.5 kcal/mole.
Conclusions
The formal kinetics of the polymerization of 9-(2-oxyethyl)carbazole methacrylate in benzene solution in the presence of dinitrile of azobisisobutyric acid has been studied; the reaction orders with respect to the monomer and initiator and the activation energy have been determined.
Literature
- I. P. Zherebtsov. Candidate of Technical Sciences dissertation. Tomsk, 1967.
- Organic Solvents, ed. A. Weissberger, IL, 1964.
- K. Laidler. Kinetics of Organic Reactions. Moscow, “Mir,” 1964.