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21CHEMICAL SCIENCES
SYNTHESIS AND STUDY OF SURFACE-ACTIVE SALTS BASED ON PROPOXY DERIVATIVES OF HEXADECYLAMINE AND MONOCARBOXYLIC ALIPHATIC ACIDS
Asadov Z.
Doctor of Chemical Sciences, professor, corresponding member of Azerbaijan National Academy of Science; head of laboratory of surfactants of Institute of Petrochemical Processes (IPCP)
Zargarova S.
Senior instructor of Baku Higher Oil School, post-graduate researcher of laboratory of surfactants of IPCP
Zarbaliyeva I. PhD (Chemistry), associate professor, leading researcher of laboratory of surfactants ofIPCP
Rahimov R.
Doctor of Chemical Sciences, associate professor, chief researcher of laboratory of surfactants ofIPCP
Huseynova S.
Scientific researcher of laboratory of surfactants ofIPCP
Baku Azerbaijan
Abstract
Salts of the oligomeric propoxy derivatives of hexadecylamine with several organic acids were synthesized. Structure and composition of the salts were confirmed by using IR spectroscopy. Surface tension and electrocon-ductivity properties of the oligomers were examined and corresponding main parameters of the salts were calculated. Moreover, petrocollecting properties of these salts were determined and maximum values of petrocollecting coefficients were calculated.
Keywords: hexadecylamine, propoxy derivative, salt, surfactant, petrocollecting
Introduction
The increasing demand to crude oil and products of its refining results in ecological instability and disbalance. In order to improve ecological balance of the nature, surfactants are used in industry including oil production and refining [1,2]. Thin oil layers on the surface of the water become one of such ecological problems which may occur during transportation of crude oil and its refining products.
According to the literature, higher aliphatic amines may be used for synthesis of surface-active compounds [3-5]. In a given study, surfactants are obtained from hexadecylamine, propylene oxide and monocarboxylic aliphatic acids. Main physical-chemical properties of the new surfactants including colloidal-chemical ones were determined in order to apply them as petrocollecting agents.
Experimental
Hexadecylamine was a product of "Alfa Aesar GmbH & Co KG" firm (Germany) of purity > 98%.
Propylene oxide was a product "Organic Synthesis" factory (Sumgayit, Azerbaijan) of 99.97-99.98% purity.
Monocarboxylic aliphatic acids were "analytically pure" grade products of Novocherkassk Plant of Synthetic Products (Russia).
Potassium hydroxide was used as "analytically pure" product of "Chemapol" firm (Czech Republic).
Oligomer of hexadecylamine and propylene oxide was synthesized at 140-150oC for 13-14 hours in an autoclave made of stainless steel and equipped with a regulator of temperature. In the given reaction, potassium hydroxide was used as a catalyst. In the second step, propoxy derivative of the hexadecylamine reacted with different monocarboxylic aliphatic acids at 50-60oC for 5-6 hours in order to obtain organic salts.
All organic salts are liquids of brown color.
IR spectra were recorded by using an ALPHA FT-IR spectrometer (Bruker,USA) using KBr tablets.
Surface tension (y) values were measured by Du Nouy ring method using a KSV Sigma 702 tensiometer (Finland).
Specific electroconductivity (k) values were determined by "Anion-4120" electroconductometer (Russia).
Resuls and Their Discussion
The reaction between hexadecylamine and propyl-ene oxide is illustrated as following:
H33C16-NH2 + nCH2-CH-CH3-
V
H33C16-N
(CH2-CH-0)mH CH3
(CH2-CH-0)kH CH3
where n=m+k.
In order to obtain organic salts, in the second step, propoxy derivative of the hexadecylamine was reacted with different monocarboxylic aliphatic acids as following:
CH3 I
(CH2-CH-0)mH H33C16-N ••• HOOC-R (CH2-CH-0)kH CH3
3349.88 cm-1 in the second spectrum and 3197.23 cm-1 in the third one represent OH valent vibration bands. CH valent vibration bands of CH3, CH2 and CH groups are observed at 2922.29-2853.09 cm-1 in the first spectrum, 2920.31 -2851.84 cm-1 in the second spectrum and at 2916.63-2849.55 cm-1 in the third spectrum.
H33Ci6-Nv
(CH2-CH-0)mH I
CH3 + R-COOH >(CH2-CH-0)kH
CH3
where R is CH3, C10H21 and C17H35. The products are defined as from Salt 1 to Salt 3, respectively to the radicals of the carboxylic acids.
Structure and composition of the final products were analyzed by using IR spectroscopy. The IR-spectra are given in Figure 1.
By examining IR spectra, it was deduced that absorption bands at 3327.87 cm-1 in the first spectrum,
Figure 1. IR spectra of the synthesized salts: a) salt 1; b) salt 2; c) salt 3
C-H deformational vibrations bands exist at
cm-1
n-l
1460.89-1378.84
cm-1
1459.23-1375.59 1462.47-1379.02 cm-1, while C-N valent vibration bands are at 1259.26 cm-1, 1284.93 cm-1 and 1285.88 cm-1, respectively in the first, second and third spectra. C-O valent vibrations band of C-OH group can be defined at 1052.22 cm-1 in Salt 1 spectrum, 1047.67 cm-1 in Salt 2 and 1088.02 cm-1 in Salt 3 spectra. (CH2)x
"pendulum"vibrations bands exist at 720.89 cm-1 in the first spectrum, 722.57 cm-1 in the second spectrum and 723.91 cm-1 in the third spectrum.
Surface tension data of Salts 1, 2 and 3 were determined at temperatures 25, 24 and 26oC, respectively. y versus concentration (c) plots of the components are given in Figure 2.
80 S 60
I 40 ^ 20
0
1» 111*.-•
0,0005 0,001 0,0015 0,002
Salt 1 Salt 2 Salt 3
0,0025
0
c, mol/l
Figure 2. Surface tension at the water-air border versus concentration plots of the salts
Bu using these plots of the salts, characteristic parameters of the surface activity can be determined. Critical micelle concentrations (CMC) of the salts were found out as 5.28*10-5, 1.78*10-5 and 3.58*10-5 mol/l respectively. Additionally, ycmc, surface pressure (ncMc), C20 (the concentration for reduction of y by 20 mN/m), adsorption efficiency (pC20 = -logC20) as well as CMC/C20 values of the all salts were determined according to [3] and given in Table 1.
Maximum surface excess concentration-rmax values were calculated from the following equation:
1 d y
rmax =--;;—™ * lim ——
n* R*T c^cCMC d Inc
where R is universal gas constant (R=8.3145 C/mol*K) and T is absolute temperature. The value of n was taken as 2 because 2 ions are formed by dissociation of the salts.
The minimum value of the area for one surfactant molecule of the salts at the water-air border (Amm) were determined by the given equation
1016
A ■ — ■
f^rnm
Na X rmax and tabulated in Table 1.
Table 1
Surface activity parameters of the synthesized surface-active salts
Surfactant CMCx105 (mol/L) YCMC (mN/m) TCcmc (mN/m) C20XIO5 (mol/L) CMC/ C20 pC20 TmaxXlO10 (mol/cm2) Ammx102 (nm2)
Salt 1 5.28 32.16 39.84 0.57 9.26 5.24 2.97 55.9
Salt 2 1.78 31.37 40.63 1.07 1.66 4.97 5.41 30.71
Salt 3 3.58 28.23 43.77 0.99 3.62 5.01 2.48 66.85
Specific electrical conductivity dependence on concentration was studied for the first salt-at 24.8oC, for the second salt-at 26.4oC and for the third salt-at
26.2oC. Isotherms of the specific electrical conductivity were plotted and given in Figure 3:
Salt 1 Salt 2 Salt 3
0 0,0005 0,001 0,0015 0,002 0,0025
c, mol/l
Figure 3. Specific electrical conductivity versus concentration plots of the obtained salts
Slopes of the straight line before (S1) and after (S2) CMC value of each salt were determined. Such thermo-dynamic properties as Gibbs free energy of micelliza-tion (AGimc) and Gibbs free energy of adsorption (AGad) values were calculated according to the following equations:
AGmic = (2-a) xRxTx \n(CMC)
AGad = (2
0.6023
a)xRxT x ln(CMC)
x ucmc x aqmc where ACMC is surface area of the one surfactant molecule at the interface in terms of Â2.
Table 2
Specific electrical conductivity parameters and thermodynamic parameters of micellization and adsorption
of the obtained salts
Surfactant a B AGmic, kJ/mol AGad, kJ/mol
Salt 1 0.29 0.71 -41.73 -43.07
Salt 2 0.03 0.97 -53.38 -54.13
Salt 3 0.02 0.98 -46.82 -48.58
As is seen, the AGad values are more negative than the AGmic values which points out to preference of the adsorption of the surfactants rather than the micelle formation.
In order to identify petrocollecting property of the surface-active salts, unthinned reagents, 5% wt. aqueous and ethanolic solutions of the salts were separately added to the water with thin petroleum layer. Thin layer
(~0.17 mm) of Pirallahi (oil field near Baku, Azerbaijan) petroleum was formed on the surface of 40 ml distilled, tap and sea (the Caspian) water in Petri dishes. For each salt, maximum duration of the petrocollecting action and maximum petrocollecting coefficient-K at room temperature were determined and given in Table 3. The value of "K" is derived as the ratio of the area of the surface of initial petroleum film and the area of the
surface of the petroleum spot formed under the action of the salts.
Table 3
Maximum duration of petrocollecting action and maximum petrocollecting coefficients of the synthesized salts
Surfactant State of surfactant Duration, hours Maximum petrocollecting coefficient
Distilled water Tap water Sea water
Salt 1 Unthinned reagent 191 39.06 36.80 36.80
5% wt. aqueous solution 33.97 33.97 33.97
5% wt. ethanolic solution 31.54 31.54 29.44
Salt 2 Unthinned reagent 191 33.97 33.97 31.54
5% wt. aqueous solution 33.97 31.54 31.54
5% wt. ethanolic solution 33.97 31.54 30.45
Salt 3 Unthinned reagent 167 22.08 11.04 11.04
5% wt. aqueous solution 12.62 9.81 9.81
5% wt. ethanolic solution 14.72 9.81 9.81
As becomes evident from the obtained data, Salt 1 and 2-Chloroethanol, Journal of Surfactants and is more effective than the other two salts. In the sea and Detergents. 2018,21. p.247-254. fresh waters, Kmax for Salt 1 is 36.8, whereas for the 4. Asadov Z., Zarbaliyeva I., Zargarova S.
other two salts this index is lower. Aqueous solution of Propoxylation of Aliphatic Amines by Propylene Salt 1 is more effective than its ethanolic solution. Oxide, Journal of Chemical Problems, 2017,1. p.44-50.
5. S.H.Zargarova, I.A.Zarbaliyeva,
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Surfactants Based on Alkylamine, Propylene Oxide
ACETYLTHIOUREA LEACHING GOLD FROM TAILS OF FLOTATION DEPOSIT DZHIKIKRUT
Kholov Kh.
Assistant of the name of V.I.Nikitin Institute of Chemistry, Academy of Sciences of the Republic Tajikistan
Samikhov Sh. Doctor of Technical Sciences, The Leading sciences of the name of V.I.Nikitin Institute of Chemistry, Academy of Sciences of the Republic Tajikistan
АЦЕТИЛТИОМОЧЕВИННОЕ ВЫЩЕЛАЧИВАНИЕ ЗОЛОТА ИЗ ХВОСТОВ ФЛОТАЦИИ
МЕСТОРОЖДЕНИЯ ДЖИЖИКРУТ
Холов Х.И.
аспирант Института химии им. В.И. Никитина Академии наук Республики Таджикистан
Самихов Ш.Р.
доктор технических наук, главный научный сотрудник Института химии им. В.И. Никитина Академии наук Республики Таджикистан
Abstract
The presented results of the study on gold leaching proved that after pretreatment of tailings, acetylthiourea satisfactorily leaches gold from them. Аннотация
Представленные результаты исследования по выщелачиванию золота доказывают, что после предварительной обработки хвостов ацетилтиомочевина удовлетворительно выщелачивает из них золото.
