Alkaline Hydrolysis Kinetics and Physico-Chemical Properties of Acrylic Copolymers Based on Acrylic Acid, Its Esters and Vinyl Acetate
Kinetic regularities of the alkaline hydrolysis of copolymers of methyl acrylate, butyl acrylate, vinyl acetate and acrylic acid of several chemical compositions under various conditions were studied by IR spectrometry. The initial rate of alkaline hydrolysis and the limiting conversion degree were shown to increase with increasing concentrations of the components of the reaction mass and temperature. The methyl acrylate units in the copolymer macromolecules hydrolyze at a higher rate than the butyl acrylate ones, while the vinyl acetate units do not participate in the alkaline hydrolysis reaction in aqueous medium. Alkaline hydrolysis of acrylic copolymers taking place, the –COO– groups, along with the retarding effect, accelerate the reaction of neighboring units by the anchimeric assistance mechanism, thereby partially compensating for the general effect of slowing down the reaction. During the reaction of alkaline hydrolysis, the relatively low-polar initial copolymers convert into polyelectrolytes with a change in the macromolecular composition and with a significant increase in the viscosity of the system. During alkaline hydrolysis, the dynamic viscosity reaches up to 120 mPa•s at a polymer concentration of about 2 wt.%. In an aqueous–alcoholic medium, due to the reactional availability of all functional groups, hydrolysis rate of the copolymer with vinyl acetate units increases because of alcoholysis of these vinyl acetate units.
1. El-hoshoudy A. N., Desouky S. M., Gomaa S. Application of Аcrylates in Enhanced Oil Recovery. J. New Develop. Chem., 2019, vol. 2, no. 3, pp. 1–17.
2. Madhuranthakam C. M. R., Alsubaei A., Elkamel A. Performance of polyacrylamide and poly (acrylamide/ sodium acrylate) hydrogel-coated mesh for separation of oil/water mixtures. J. Water Proc. Eng., 2018, vol. 26, pp. 62–71.
3. Aalaie J., Vasheghani-Farahani E., Semsarzadeh M. A., Rahmatpour A. Gelation and swelling behavior of semiinterpenetrating polymer network hydrogels based on polyacrylamide and poly(vinyl alcohol). J. Mac romol. Sci. Part B: Physics, 2008, vol. 47, no. 5, pp. 1017–1027.
4. Tong D., Yesiloz G., Ren C. L., Madhuranthakam C. M. R. Controlled synthesis of poly (acrylamide-co-sodium acrylate) copolymer hydrogel microparticles in a droplet microfluidic device for enhanced properties. Industr. & Eng. Chem. Research., 2017, vol. 56, no. 51, pp. 14972–14979.
5. Craciun G., Ighigeanu D., Manaila E., Stelescu M. D. Synthesis and characterization of poly (acrylamide-co-acrylic acid) fl occulant obtained by electron beam irradiation. Mate. Research., 2015, vol. 18, no. 5, pp. 984–993.
6. Qi X., Liu M., Chen Z. Study on swelling behavior of poly (sodium acrylate- co- 2- acryloylamino- 2- methyl1-propanesulfonic acid)/attapulgite macroporous superabsorbent composite. Polym. Engin. & Sci., 2015, vol. 55, no. 3, pp. 681–687.
7. Matsui D., Ishimaru S. Synthesis and swelling behavior of nanocomposites consisting of clay and poly (N-isopropylacrylamide-co-sodium acrylate). Clay Sci., 2018, vol. 22, no. 4, pp. 103–109.
8. Plate N. A., Litmanovich A. D., Kudryavtsev Ya. V. Reactions in polymer blends: Experiment and theory (A review). Polymer Science. Series A, 2004, vol. 46, no. 11, pp. 1108–1140 (in Russian).
9. Plate N. A., Litmanovich A. D., Kudryavtsev Ya. V. Makromolekulyarnye reakcii v rasplavah i smesyah polimerov: teoriya i eksperiment [Macromolecular reactions in melts and blends of polymers: theory and experiment]. Moscow, Nauka Publ., 2008. 380 p. (in Russian).
10. Obshicer A. S., Romanova Yu. O., Bajburdov T. A. Shchelochnoj gidroliz sopolimerov na osnove efi rov akrilovoj kisloty [Alkaline hydrolesis of copolymers based on esters]. Dostizheniya molodyh uchenyh: himicheskie nauki: tez. dokl. IV Vseros. molodezh. konf. [Achievements of young scientists: chemical Sciences: abstracts of the IV all-Russian youth conference]. Ufa, RIC BashGU, 2018, pp. 188–191 (in Russian).