CC BY
45
Section 11. Chemistry
References:
1. Vladimir Loginov. Oil dehydration and desalting.//“Chemistry”, M.: 1979. P. 216.
2. Petrov A. A. The nonionic-demulsifiers for oil dehydration.//“Kuibyshev book. ed. “, 1965. P.143.
3. Myshkin E. A.. Preparation of oil and fuel for processing.//Gostoptekhizdat, M.: 1946. P. 119.
4. Pozdnyshev G. N. Stabilization of emulsions and destruction. “Nedra”, M.: 1982. 222 p.
Muhamadiev M. G., National University of Uzbekistan, Associate Professor the Faculty of Chemistry Khazratkulova S. M., National University of Uzbekistan, teaching assistant the Faculty of Chemistry Mahkamov M. A., National University of Uzbekistan, teaching assistant the Faculty of Chemistry E-mail: sevara.hazratqulova.83@mail.ru
Physic-chemical characteristics of polymers on the basis N- replaced acrylamides of natural ox acids
Abstract: Studying the influence of pH and the temperature of the environment to viscosity of water solutions, swelling kinetics and collapse of cross-linked polymers and copolymer on the basis of natural ox acids there are founded the presence of pH and heat-sensitive qualities. It is revealed that the existence of polymers as a form of amides and as well as carboxyl groups leads to the appearance of a unique quality of having a little interval of temperature of two critical mixed temperatures.
Keywords: PAA-N-MLA — Acrylamide N is methylene of laced acid, PAA-N-MGA — Acrylamide N is methylene of glekilev acid, PAA-N-MLA and PAA-N-MGA are dissolved in water, methanol, ethanol, DMFA, DMCO and some other polar dissolvent. They are not dissolved in ether, benzol, and hydrocarbon.
It is known that physic -chemical characteristics of macromolecular repulsive forces between charged groups solutions of polyelectrolytes particularly differ with their ofthe same name lead to considerable change conformation
peculiarities from non electrolyte polymer. Presence ofmolecules in solution. The consequence of it is deflection
of ionized groups have an effect on viscosity by ionizing of the rectilinear dependence. qyA/C=f (С).
а) б)
PAA-N-MGA from polymer concentration. concentration.
118
Physic-chemical characteristics of polymers on the basis N- replaced acrylamides of natural ox acids
As it is seen from pictures, when water solutions PAA-N-MMA and PAA-N-MGA are mixed, the viscosity of solutions strongly increased.(pic.1)Such anomaly dependence is typical for polyelectrolyte; it is explained through well-known effect of polyelectrolyte’s swelling. Since PAA-N-MLA and PAA-N-MGA are polyelectrolyte and when their water solutions are mixed straightening of ionization of carboxyl groups of macromolecular happens, which causes swelling of polymer chains.
Equation of Fuoss was used for processing the following viscosity measurement of water solutions PAA-N-MMA and PAA-N-MGA.[1].
С = - + -sic
Пуд А А
In coordination with this equation occurs straightening of dependence curve of the given viscosity of solutions of polymers from concentration, which is typical for polyelectrolyte. Ionized polyelectrolyte’ existence strongly effects on viscosity of concentrated solutions, where sharply occur intermolecular interactions, it also effects well on mixed solutions where repulsion forces which appear as a result of polymer ionization, lead to significant growth of viscosity because of polyelectrolyte swelling macromolecules. The consequence is deflection of straight-line dependence. qy\/C=f(C).
The viscosity of gomopolymer solutions AA-N-MLA was studied in water solutions. In the picture 1 there is given dependence пуд/С from С. It shows that the de-
a)
pendence has anomaly character as for water solutions of typical polymer polyelectrolyte.
Expansion of target viscosity water solution poly -AA-N-MLA under mixture is conditioned additional disassociation of carboxyl groups that forces electro statistical repulsion of affectionate links. As far as mixing there is increased effective supply of macromolecules and it leads to extra swelling of macromolecules.
The swelling can be removed by putting some neutral low molecular electrolyte in excess supply into the solution, while it is being mixed salt concentration is increased the viscosity of polymer is decreased and under potassium chloride concentration 0,5 M the dependence assumes a straight -line character.
It is known that acidifying of the polymer solutions with acid functional groups makes ionization complex.
By selection there was established that under little concentration HCI in the solutions of PAA-N-MLA and PAA-N-MGA “anomaly" ofviscosity disappears. In 0,001 molar solution HCI dependence пуд/С from C for water solutions PAA-N-MLA and PAA-N-MGA represents straight-line dependence which is typical for polymer and not for electrolytes. The absence of anomalous motion curve ionization is conditioned by suppression of carboxyl groups in acid medium.
The dependence of the viscosity solutions of PAA-N-MLA (a) and PAA-N-MGA (b) from concentration of polymer 0,001m in the solutions HCI.
6)
For describing molecular mass polymers there was investigated their characteristic viscosity in solutions 0,001
m in the solution of polymer initiation AA-N-MMA of concentration (3a), monomer (3b) and PH medium (3c).
119
Section 11. Chemistry
There were received analogical results on measuring viscosity for poly AA-N-МГА. As it is seen in the pictures, viscosity characteristics of polymers decrease by increasing initiator concentration according to change of polymerization under different PH medium.
There was examined water solution viscosity of copolymers AA-N-MLA with N.N -PEAA of different basis under different temperature; for exploring thermo sensitive characteristics of copolymers. For heat increase the viscosity of solutions increases which is typical for a system with low critical temperature mix.(HKTC). Besides, viscosity of solutions of copolymers containing 80 mol %N,N-DEAA is less than in copolymer containing 50 mole % N,N-DEAA the reason of observing effect is as follows, with decreasing temperature dissolubility of copolymers grows (this quality is typical for a system with (HKTC) its macromolecule straightens and viscosity medium increases. However, with a 20 mole% N,N - DEAA content, viscosity of solution within increase of temperature grows, that what is typical for a system of critical heat shift.
Consequently, little substance content dielectryla-mid does not allow copolymer to demonstrate low heat thermo sensitive qualities.
As it is seen from shown data on potentiometer titration of water solutions PAA-N-MLA and PAA-N-MGA with solutions Na OH .
There is observed a noticeable jump, testifying the existence of acid groups in the compound of polymers.
Calculations which are made on the basis of curve po-tentiometric titration showed that significance of equivalent of functional groups are equal to theoretical calculation, which practically corresponds with molecular mass unit of polymer and serves as additional evidence in identification of polymer’s structure. According to determination acidity oftitration in equation coordination’s ofHnederson-Hassel-bah, it is visible that importance pK polymers grow with the increase ofthe matter a , which is typical for polyelectrolytes considering that, the importance of pK grows by increasing a, and equation of Henderson-Hasselbah in the target system will have the following form [2] :
РК о = РН - lg~a + APK(a),
1 -a
Where АрК (a)-contribution of different energy in alteration of free enthalpy ofpolyelectrolytes association reaction, for instance: electro statistical, conformational, solvational, and others.
As it seen in picture 3.1.4 curved potentiometric titration of solutions PAA-N-MMA and PAA-N-MGA in coordination’sрК a=f(a) several ones differ from one another; for PAA-N-MLA and PAA-N-MGA curve motion has a straight-line character, therefore on the basis
of the chart of dependence experienced matters from a
a
under extrapolation into рК0 = рН — lg------ Matters
1 — a
pK0 received by extrapolation matter pK0 on zero matter a, for PAA-N-MMA equals to 4,0 for PAA-N-NGK equals to 3.8In that way, polyelectrolyte quality of water solutions PAA-N-MLA and PAA-N-MGA are identified, on the basis of research of hydrodynamic characteristics. And on the basis of the following pothenmet-ric titration of water dissolvement PAA-N-MLA and PAA-N-MGA are estimated the matters pKa which equals to 4.0 and 3.8.
Experimental part
a) Synthesis of monomers
Acrylamide N is methylene of laced acid. 7.1g (0,1 mol) acrylamide, 3g (o.1 mol) formalin, 9g (0.1 mol) milk acid and 0.003g (0.002 mol) hydroxinon were put in flask with a mixer. Substance was mixed under temperature 333K during 3 hours. Target product was cleaned from unreacted components with consistent extraction of tetrachloride carbon chloroform. Monomer represents red yellow, viscose liquid with specific smell. Output of the production included 70%.
b) Synthesis of polymers
Polymerization of received monomers were tested in water dissolvement in glass ampules. After filling ampules with necessary amount of initial reagents, the ampules were decontaminated in vacuum till the residual pressure 10 , were unsolded and polymerized in thermostat under temperature 333K. Monomer concentration consisted of 5%, and initiator concentration 1%.
In the capacity of initiator there were utilized dinitrile acid received polymers were distinguished besieging in isopropyl alcohol and dried in vacuum in executor until permanent mass.
References:
1. Fuoss R. M., Strauss U.P.Polyelectrolites II. Ply-4vinylpyridonium chloride and poly-4-vinyl-N-bynylpyridonium bromide//J. Polym. Sci. -New York, 1948. - V. 3. - P. 246-263.
2. Rice S.A., Nagasawa M.Polyelectrolyte Solutions, a theoretical introductions - London-New-York: Acad. Press, 1961. - 124 p.
120
