652 DOI: 10.17344/acsi.2014.1296 Acta Chim. Slov. 2015, 62, 652-661 Scientific paper New Method of Synthesis of Oligoetherols with Carbazole Ring Renata Lubczak Rzeszów University of Technology, Department of Organic Chemistry, Al. Powstanców Warszawy 6, 35-959 Rzeszów, Poland * Corresponding author: E-mail: rlubczak@prz.edu.pl Received: 12-12-2014 Abstract The new method of synthesis of multifuntional oligoetherols with carbazole ring suitable for obtaining the polyurethane foams of enhanced thermal resistance was presented. At the first step of the synthesis the carbazole was reacted with excess glycidol to obtain the product of (n +1) functionality, where n is number of equivalents of glycidol reacted with carbazole. This semiproduct was then reacted with oxiranes like ethylene and propylene oxides or alkylene carbonates like ethylene and propylene carbonates. The progress of reaction as well as structure of the products were studied by classic and instrumental methods like elemental analysis, IR, 1H-NMR, and MALDI-ToF spectroscopies. Some physico-chemical properties of the products were described. Keywords: Carbazole, glycidol, hydroxyalkylation, oligoetherols, structure, properties 1. Introduction Carbazole is aromatic three ring heterocycle. Chemical properties are similar to other nitrogen-containing hete-rocycles like indole, pyrrol and secondary aromatic amines. It is weakly acidic due to the presence of nitrogen-attached hydrogen.1 Carbazole and its derivatives are used in chemistry and technology of polymers, dyes, herbicides, surfactants, and other polymer additives.2-8 Some derivatives of carbazole reveal unique physical properties like photo- and electroluminescence, liquid crystallinity, electric conductance, and nonlinear optical properties.9-15 Their properties render them promising structural component in electronic devices and related areas. Carbazole ring is thermally resistant; its decomposition starts at 260 °C. Introducing the carbazole into oligoetherols results in increase of thermal resistance of oligoetherols as well as pol-yurethanes and polyesters obtained from them.16-22 Because carbazole is monofunctional compound it cannot be applied straightforward to get the oligoetherols. Up to date, the attempts to increase its functionality resulted in formation of products which were difficult to isolate and purify. Thus the linear oligoetherols were obtained by its reaction with glycerol epichlorhydrin to give 9-(2,3-epoxy-propyl)carbazole followed by epoxide ring opening with water, ethylene glycol or ethanolamine, and further con- version by reaction with oxiranes to get finally bi-functio-nal oligoetherols.16-18 In another procedure the oligoetherols were obtained in multistep reaction sequence: the reaction of carbazole with ethylene chloride, then with diethanolamine to get diol, which finally was reacted with oxiranes.18 Initially obtained 9-(2,3-epoxypropyl)carbazo-le was also converted into multifunctional product by ring opening with glycerol or sorbitol.20,22 These products were then hydroxyalkylated with oxiranes and further used to obtain linear polyurethanes (PU) and PU foams of good thermal resistance. The multistep procedure can be simplified by using the excess glycidol reacting with carbazole. Here the protocol leading to multifunctional derivatives (oligoetherols) is described, together with the structure and properties of products, which are suitable substrates to obtain PU foams of enhanced thermal resistance. 2. Experimental Section 2. 1. Syntheses 2. 1. 1. Reactions of Carbazole with Glycidol Carbazole (4.2 g, 0.025 mol), 1.85-12.95 g (0.0250.200 mol) glycidol and 5 g N,N-dimethylformamide (DMF as solvent) were placed in three-necked 100 cm3 flask equipped with mechanical stirrer, reflux condenser and thermometer. The content was heated up to 120 °C. The exothermic reaction was initiated and temperature of the mixture raised to 145 °C at which the process was continued. In another protocol the reaction was performed at 120 °C using more DMF (10 g). The reaction progress was followed by determination of epoxide number (EN). After the reaction mixture was cooled down to room temperature the precipitate was formed. Water (50 cm3) was added and the mixture was heated until the precipitate turned to resin. Upon cooling down the precipitate formed again, which was filtered off, washed with water and vacuum dried. The filtrate was concentrated by evaporation of water; from the filtrate second batch of product was obtained, which was worked up in analogous way. 2. 1. 2. Synthesis of Semiproduct for Synthesis of Oligoetherols Carbazole (10.0 g, 0.06 mol) and 12.0 g (0.16 mol) DMF were placed in three-necked 250 cm3 flask equipped with mechanical stirrer, reflux condenser and thermometer. The mixture was stirred and heated till carbazole (C) was dissolved (93 °C). To this mixture 31.1 g (0.42 mol) glicydol (GL) was added in one portion. The mixture was kept at 120 °C for one hour. The progress of reaction was controlled by determination of unreacted glycidol and EN. Then the solvent was removed under reduced pressure (p = 12 hPa). 2. 1. 3. Reaction of Semiproduct with Oxiranes The product of reaction C : Gl = 1:7 (30.0 g, 0.044 mol), triethylamine as catalyst (2 cm3, 0.014 mol), and propylene oxide (PO, 21.7 g, 0.368 mol) or in another synthesis 10.5 g PO (0.178 mol) and then ethylene oxide (EO, 12.0 g, 0.273 mol) were placed in 100 cm3 pressure reactor equipped with magnetic stirrer and thermometer. The mixture was stirred and kept at 55-65 °C. The completion of reaction was determined by EN measurement. 2. 1. 4. Reactions of Semiproduct with Alkylene Carbonates The product of reaction C : Gl = 1:7 (38.0 g, 0.055 mol), potassium carbonate catalyst (0.1 g, 7,25-Ю-4 mol), and ethylene carbonate (EC, 39.0 g, 0.44 mol, to keep initial molar ratio of reagents as 1:8 ) or propylene carbonate (PC, 34.9 g, 0.342 mol, to keep initial molar ratio of reagents as 1:6) were placed in three necked 250 cm3 flask equipped with stirrer, thermometer and reflux condenser. The mixture was heated up and kept at 180 °C until dissolving of substrate. The reaction progress was checked using mass balance and determination of amount of unreac-ted alkylene carbonate. 2. 2. Analytical Methods The progress of reactions with oxiranes and glyci-dol were monitored by determination of epoxide number using hydrochloric acid in dioxane method.23 The course of reaction between semiproduct and EC or PC was followed by measuring the content of unreacted alkylene carbonate.24 Elemental analysis for C, H, N, were done with EA 1108, Carlo-Erba analyzer. The IR spectra of products were recorded with Specord 71 IR, Carl Zeiss spectrophotometer in capillary film or in KBr pellet; the 1H-NMR spectra were recorded at 500 MHz, BECK-MAN DU-640 spectrometer in d6-DMSO, with HMDS internal reference. MALDI ToF (Matrix-Assisted Laser Desorption Ionization Time of Flight) of oligoetherols were obtained with BRUKER Autoflex Speed (Bruker Daltonik, Germany) mass spectrometer working at linear mode with delayed ion extraction, equipped with nitrogen laser working at 337 nm. The method of laser desorption from matrix (silver plate) was used. The samples were diluted to 1 mg/cm3 concentration with methanol. Therefore the observed peaks corresponded to the molecular ions plus methanol and Ag+ and K+ (from catalyst) ions. Thermal analyses of products (DTA, DTG and TG) were performed in ceramic crucible at 20-1000 °C temperature range, about 200 mg sample, under air atmosphere with Termowaga TGA/DSC 1 derivatograph, Mettler. 2. 3. Properties of Oligoetherols Refraction index, density, viscosity, and surface tension of oligoetherols were determined with Abbe refracto-meter, pycnometer, Höppler viscometer and by the detaching ring method, respectively. 3. Results and Discussion Preliminarily the reaction of carbazole with glycidol without solvent was performed at the carbazole : glycidol molar ratio 1 : 1-1 : 10. Even upon prolonged heating at 150-190 °C the mixture remained unreacted. In the presence of TEA catalyst still carbazole remained untouched while glycidol converted into polyglycidol products. In order to provide homogeneous conditions of reaction the DMF was used as solvent, in which carbazole does dissolve. The advantage of the glycidol substrate is its ability to react with carbazole consecutively as shown in the scheme below: Initially the reaction was performed at 145 °C with the C:GL 1:1-1:6 molar ratio mixtures (Table 1). The resin product and precipitate were obtained upon distillation DMF off. The precipitate was identified as carbazole by 1H-NMR spectroscopy, by presence of characteristic resonance at 11.25 ppm of NH proton (Fig. 1). Thus, the rest trifunctional compound Scheme 1. Reaction of carbazole with excess of glycidol Fig. 1. 1H-NMR spectrum of post-reaction mixture obtained from the C : GL = 1 : 1 molar ratio system of carbazole in post-reaction mixture was converted into bi- and trifunctional consecutive products. The mixture components were separated as described in Experimental. Based upon nitrogen percentage in carbazole and CPD (the product obtained from C:GL = 1:1 reaction system, see scheme 1), the composition of precipitate and resin was calculated. It has been found that upon increase of glycidol content in reaction system the less precipitate was formed (Table 1, column 8). Thus at the system of 1:7 molar ratio the carbazole no longer precipitated from post-reaction mixture. The nitrogen percentage in precipitate was between 6.3 and 4.7 %, which indicates the presence of unreacted carbazole (% N= 8.38) and reaction products C : GL = 1:1 (CPD, % N = 5.81) or C : GL = 1:2 (% N = 4.44) in reaction post-mixture (Table 2, columns 11 and 12). The presence Table 1. Analysis of reaction progress and products of reaction between carbazole and glycidol C : GL molar ratio Composition of Tempe- Reaction Composition of post- Entry initial mixture rature time reaction mixture determined [mass %] [°C] [min] form mass balance C GL DMF precipitate resin 1 2 3 4 5 6 7 8 9 1 1 1 37.8 17.1 45.1 145 30 33.7 61.3 2 1 2 32.6 28.7 38.7 145 50 29.7 70.3 3 1 3 28.4 37.8 33.8 145 55 17.4 82.6 4 1 4 25.3 44.6 30.1 145 60 13.6 86.4 5 1 5 22.8 50.2 27.0 145 60 10.4 89.6 6 1 6 20.6 54.9 24.5 120 70 6.8 93.2 7 1 6 16.6 44.0 39.4 120 105 3.1 96.9 8 1 7 18.9 58.6 22.5 120 75 0.0 100 of carbazole in precipitate was confirmed by the resonance of NH carbazole in the 1H-NMR spectrum. The 1H-NMR spectra of resins did not show this resonance. Generally the reactivity of glycidol towards hydrox-yalkyl derivatives of carbazole is higher in comparison with its reactivity towards carbazole itself. Therefore in order to obtain the products without precipitate the reaction had to be performed with large excess of GL; C:GL 1:n, where n > 7. In such protocol the carbazole derivatives containing many hydroxyl groups are formed, which are well soluble in oxirane and react with them in presence of TEA catalyst to give oligoetherols with included carbazole ring. The product of C : GL = 1:7 reaction dissolved in PO at 60-70 °C. After addition of TEA into the reaction mixture placed in pressure reactor the multifunctional oli-goetherol of C : GL : PO = 1:7:8 molar ratio was obtained. In another reaction the mixture of PO and EO was used and the oligoetherol of average composition C : GL : PO : EO = 1:7:4:6 was obtained. In further step the oxiranes were replaced with alkylene carbonates. The semiproduct of C : GL = 1:7 reaction resulted in formation of analogous products as those obtained with oxiranes, according to the scheme 2: In contrary to oxiranes, which are cancerogenic and able to form explosive mixture with to air, the alkylene carbonates are not hazardous.25 Moreover, alkylene carbonates have lower boiling temperature and thus do not require high pressure reactors. The product of reaction in the C:GL = 1:7 system is well soluble in alkylene carbonates upon heating to 60-70 °C and readily react with them in presence of potassium carbonate catalyst to give oligoetherols with incorporated carbazole ring. The process was preformed at 180 °C within 8 hours. The structure of products (I) is in accordance with elemental analysis results (Table 3). The progress of reaction between carba-zole and glycidol and further with oxiranes or alkylene carbonates was monitored by IR and 1H-NMR spectros-copy of substrates, semiproducts and products. In the IR spectrum of carbazole the valence and deformation bands of NH group were observed at 3419 and 1451 cm-1, respectively. Deformation bands of aromatic C-H were found at 757-728 cm-1 region. The -NH- bands are not present in the IR spectrum of product of reaction performed in the C:GL = 1:7 system (Fig. 2). Instead the broad band of -OH group appears, as well as the band at 1100 cm-1 attributed to C-OH group. Upon reaction also the et- Table 2. Elemental analytical results of products of reaction of carbazole with glycidol C : GL molar ratio Elemental percentage [mass %] precipitate resin Estimated Estimated composition composition of precipitate of resin C : GL N C H N C H 1 2 3 4 8 9 10 11 12 1:1 6.29 76.28 6.02 2.15 49.28 8.26 mixture C + CPD 1:7 1:2 6.28 75.34 5.99 1.20 45.02 8.56 mixture C + CPD 1 13 1:3 5.49 71.93 6.24 1.40 50.20 8.24 CPD 1 11 1:4 5.57 72.78 6.90 1.42 50,30 9.19 CPD 1 11 1:5 5.53 71.54 6.22 1.38 49.95 8.17 CPD 1 12 1:6 4.73 67.56 6.86 1.30 50.63 8.49 C:Gl = 1:2 1 12,5 1:7 — — — 2.18 55.38 8.00 — 1 7 Calculated elemental percentages [mass %] Carbazole: N 8.37; C 86.12; H 5.38 CPD: N 5.81: C 74.62; H 6.22 product C:GL = 1:2 : N 4.44: C 68.57 ; H 6.60 where: R = -H, -CH3 Scheme 2. Reaction of oxirane and alkylene carbonate with hydroxyl group (I) where: R = -H, CH„ x = 7-number of oxyalkylene units from glycidol z + y = n n-number of oxyalkylene units from oxirane or alkylene carbonate Scheme 3. General formula of oligoetherol obtained from carbazo-le, glycidol and oxiranes or alkylene carbonates her C-O-C are formed, to which the band at 1039 cm-1 belong. In the product the carbazole ring remains as is evidenced by 753 and 725 cm-1 bands. In the IR spectrum of glycidol the oxirane ring bands is present at 1240 cm-1. This band disappears in the product derived from C:GL = 1:7 system, indicating the glycidol ring opening takes place (Fig. 2). IR spectra of oligoetherols (Fig. 3) obtained from the semiproduct synthesized in the C : GL = 1:7 system with oxiranes (EO and PO) or alkylene carbonates (EC, PC) are almost analogous and similar to that of the semi- Fig. 3. IR spectrum of oligoetherol obtained from C : GL :EO:PO = 1 : 7 : 4 : 6 molar ratio system product obtained from C : GL = 1:7. However the band intensity differences are relevant, especially that of the valence -OH in relation to valence C-H band (3051-2869 cm-1) and C-O-C band (1078-1067 cm-1). The latter increase in intensity indicating the number of oxyalkylene units grows as a result of ring opening of oxirane and alkylene carbonates. The characteristic bands at 753 and 725 cm-1 in products evidence the presence of carbazole ring in the products. In the 1H-NMR spectrum of carbazole the aromatic proton resonances occur at 7.1-8.1 ppm region, while the -NH- proton resonance is present at 11.25 ppm. The -NH- Fig. 2. IR spectrum of product of reaction obtained from the C : GL = 1 : 7 molar ratio Fig. 4. 'H-NMR spectrum of semiproduct obtained from C : GL = 1 : 7 molar ratio Table 3. Elemental analysis data of oligoetherols Elemental percentage [mass %] Initial reagent molar ratio calculated determined C N H C N H C : GL = 1: 7 57.80 2.04 7.50 57.61 2.13 7.42 C :GL : EO : PO = 1:7:4:6 57.13 1.26 7.15 56.96 1.37 7.32 C :GL : PO = 1:7:8 65.43 1.34 8.77 65.60 1.29 8.52 C : GL: EC = 1:7:8 60.75 1.65 7.49 60.69 1.42 7.30 C : GL : PC = 1:7:6 63.87 1.66 7.89 63.75 1.59 7.80 proton resonance is absent in the spectrum of semiproduct obtained from C:GL = 1:7 (Fig. 4) clearly demon-strating this group has reacted with glycidol. The resonances of methylene and methine protons at 3.2-4.0 ppm region in the spectrum of the semiproduct indicate the glycidol ring opening. The -OH proton resonances are present in the 4.2-5.2 ppm region attributed to various hydroxyalkyl groups. The -OH protons could be selectively exchanged to deuterium upon addition of D2O. Still the carbazole aromatic proton resonances are present within 7.1-8.1 ppm region. In the 1H-NMR spectra of products of reaction between semiproduct obtained from C: GL = 1:7 system and oxiranes (Fig. 5) the aromatic resonances remain. More complicated spectrum can be seen in the 3.0-4.0 ppm, where oxyalkylene group resonances are present. Moreover, the additional resonances at 0.7-1.2 ppm from methyl groups are observed due to ring opening of PO in the product. The 1H-NMR spectra of products obtained from semiproduct C : GL = 1:7 and alkylene carbonates are similar to those obtained from oxiranes indicating the structure of the products is similar in both cases. In the spectra of the products obtained from PC the methyl group proton resonances are observed at 0.9-1.2 ppm. MALDI-TOF spectra of the products provide more information. In the spectrum the semiproduct obtained from C: G = 1:7 the glycidol peak, which M/z is increased by silver ion due to silver plate matrix used (Table 4, entry 2). Observed peaks are derived from products with varying degrees of addition of glycidol to carbazole. The peak of highest M/z corresponds to the product of C:GL = 1:8 stoichiometry (Table 4, entry 18). Thus the stoic-hiometry in the products is not larger then initial molar Fig. 5. 'H-NMR spectrum of oligoetherol obtained from the C : GL :EO:PO = 1 : 7 : 4 : 6 molar ratio system ratio of reagents used in synthesis. In the MALDI-TOF spectra of oligoetherols the series of peaks differing of 58 in case of PO substrate and differing of 44 and 58, in case of using both EO and PO substrates are observed (Table 5). In the spectra of oligoetherols the series of peaks are observed differing by number of units originate from glycidol, to which PO is attached providing variable amount of oxypropylene units and then to this product variable amount of EO substrate is attached. Thus the product is a mixture of oligoetherols of different molecular mass. Also in the spectra of oligoetherols obtained from PC the series of peaks differing by M/z = 58 are observed due to attachment of variable amount of oxy-propylene units formed upon PC ring opening. The absence of peak differing by M/z = 44 in the spectrum of Table 4. MALDI-ToF analysis of product obtained from the C : GL = 1:7 system Entry Position of Relative signal Putative structure Calculated molar signal M/z intensity [%] of molecular ion mass [g/mol] 1 106.9 25.8 Ag+ 107 2 180.2 100 GL + Ag+ 181 3 241.1 84.3 C + GL 241 4 297.1 84.3 C + 2 GL-H2O 297 5 315.1 83.2 C + 2 GL 315 6 347.9 4.5 C + GL + Ag+ 348 7 389.2 29.2 C + 3 GL 389 8 422.2 6.7 C + 2 GL + Ag+ 422 9 463.6 5.6 C+ 4 GL 463 10 496.8 5.6 C + 3 GL + Ag+ 496 11 538.3 2.3 C + 5 GL 537 12 554.7 2.3 C + 5 GL + H2O 535 13 572.0 4.5 C + 4 GL + Ag+ 572 14 630.4 1.1 C+ 5 GL-H2O + Ag+ 628 15 647.9 2.3 C + 5 GL + Ag+ 646 16 704.8 1.1 C + 6 GL-H2O + Ag+ 703 17 804.1 1.1 C + 7 GL + Ag+ + H2O 810 18 880.3 1.1 C + 8 GL + Ag+ + H2O 884 GL-oxyalkylene group form ring decomposition of glycidol the product obtained from PC, corresponding to -COO- in oligoetherol. Therefore, the reaction does not occur ac-fragment clearly indicates the absence of carboxyl group cording to the scheme 4: Scheme 4. Reaction of hydroxyl group with propylene carbonate to form the ester group Table 5. MALDI-ToF analysis of oligoetherol obtained from the C : GL : PO : EO = 1:7:4:6 molar ratio Entry Position of signal M/z Relative signal intensity [%] Putative structure of molecular ion Calculated molar mass [g/mol] 1 248.1 100 C + GL-H2O + Na+ 246 2 262.2 56.5 C + GL + Na+ 264 3 273.2 43.1 C + GL + CH3OH 273 4 276.1 27.9 C + GL + H+ + CH3OH 274 5 278.0 92.4 C + GL + Na+ 278 6 292.2 99.0 C + GL + EO-H2O + Na+ 290 7 299.2 8.4 C + GL + PO 299 8 306.1 25.8 C + GL + PO-H2O + Na+ 304 9 308.2 11.4 C + GL + EO + Na+ 308 10 322.2 38.3 C + GL + PO+ EO-H2O 325 11 336.3 79.7 C + 2 GL + Na+ 338 12 338.1 14.8 C + GL + 2 PO-H2O 339 13 343.1 16.0 C + GL + PO + EO 343 14 350.2 12.8 C + GL + PO + EO-H2O + Na+ 348 15 352.0 11.8 C + 2 GL + PO-H2O 355 16 357.2 29.8 C + 2 GL + PO 357 17 366.1 22.4 C + GL + PO + EO + Na+ 366 18 369.1 14.8 C + GL + PO + EO-H2O 369 19 373.2 11.0 C + 2 GL + PO 373 20 380.3 37.1 C + GL + 2 PO + Na+ 380 21 431.3 18.1 C + GL + PO + EO 431 22 441.1 28.9 C + GL + 2 PO + EO-H2O 441 23 457.0 5.4 C + GL + PO + 4 EO-H2O 457 24 461.) 5.4 C + GL + 3 PO + EO + H+ 460 25 471.0 8.0 C + GL + 2 PO + 3 EO-H2O 471 26 475.3 10.6 C + 2 GL + 2 PO + EO 475 27 489.3 8.0 C + 2 GL + PO + 3 EO-H2O + H+ 488 28 505.3 12.4 C + 2 GL + PO + 3 EO 505 29 582.8 7.8 C + 2 GL + 3 PO + 2 EO-H2O + Na+ 582 30 592.2 10.0 C + 3 GL + 2 PO + 2 EO 593 31 606.1 9.0 C + 2 GL + 2 PO + 4 EO 607 32 607.4 11.6 C + 2 GL + 2 PO + 4 EO 607 33 620.2 12.6 C + 3 GL + 2 PO + 3 EO-H2O + H+ 620 34 621.4 9.3 C+ 5 GL + PO + EO-H2O 621 35 637.4 8.6 C + 3 GL + 2 PO + 3 EO 637 36 650.4 6.4 C + 3 GL + 3 PO + 2 EO 651 37 681.1 6.6 C + 3 GL + 2 PO + 4 EO 681 38 695.0 5.8 C + 3 GL + 3 PO + 3 EO 695 39 755.5 4.2 C+ 3 GL + 4 PO + 3 EO + H+ 754 40 769.5 3.1 C + 4 GL + 3 PO + 3 EO 769 C + 7 GL + PO + EO-H2O 769 GL, PO, EO-oxyalkylene group originate from ring decomposition of glycidol, propylene and ethylene oxides, respectively This is confirmed by the IR and H-NMR spectrum of the product obtained from PC, which is analogous to that obtained from PO. The semiproduct obtained from carba-zole and glycidol loses water, especially when the process is conducted at high temperature (120-145 °C; Table 5, entries .8, 10, 12, 14, 15,18, 22, 23, 25, 27, 33, 34, 40). This process in undesired, because it leads to formation of unsa-turated fragment according to the scheme below: However this process is negligible as can be estimated from the 1H-NMR spectra of oligoetherols, in which olefin proton resonances are absent. Thermal analysis of the products (Table 6) indicated that the highest thermal stability showed semiproduct obtained from carbazole and glycidol and the oligoetherols obtained from oxiranes. The 10% decomposition starts at ca 192-213 °C, and maximum decomposition temperature is 360 °C. Thus thermal resistance of obtained oligoet-herols is high. Thermal resistance of oligoetherols obtained from alkylene carbonates is slightly lower. Their decomposition starts already at 130 °C. The lower thermal resistance on these cases in probably related to the presen- Table 6. Comparison of thermal resistance of oligoetherols Oligoetherol Tio% [°C] T25% [°C] T50% [°C] T75% [°C] T T°C] max. decomposition L J C : GL = 1: 7 192 240 310 352 360 C :GL : EO : PO = 1:7:4:6 213 274 332 367 360 C :GL : PO = 1:7:8 209 274 333 365 310 C : GL: EC = 1:7:8 132 211 328 371 401 C : GL : PC = 1:7:6 160 227 319 366 395 Tx%-temperature; of x% mass loss Table 7. Physical properties of oligoetherols Oligoetherol Temperature Refraction Density Viscosity Surface tension [°C] index nD [g/cm3] [mPa • s] [N/m] • 103 20 1.5157 1.170 43682 59.5 30 1.5120 1.164 15042 57.2 40 1.5090 1.156 4747 54.6 C :GL : EO : PO = 1:7:4:6 50 1.5058 1.149 1867 52.3 60 1.5025 1.142 841.6 49.8 70 1.4991 1.135 434.3 47.7 80 1.4964 1.128 227.7 45.6 20 1.5104 1.141 61301 59.9 30 1.5072 1.133 16818 51.5 40 1.5038 1.124 5178 44.8 C :GL : PO = 1:7:8 50 1.5002 1.113 1957 38.9 60 1.4969 1.106 1618 31.1 70 1.4936 1.099 375.1 23.6 80 1.4905 1.090 180.1 17.5 20 1.5235 1.184 10928 20.00 30 1.5197 1.178 4222 19.47 40 1.5158 1.171 1625 19.00 C : GL: EC = 1:7:8 50 1.5128 1.163 707.3 18.58 60 1.5089 1.155 384.1 18.16 70 1.5049 1.148 205.4 17.64 80 1.5009 1.142 120.5 17.29 20 1.5192 1.155 26525 19.14 30 1.5162 1.149 8982 18.47 40 1.5124 1.140 3630.8 17.78 C : GL : PC = 1:7:6 50 1.5089 1.133 1513 17.15 60 1.5054 1,126 642.0 16.74 70 1.5019 1,119 298.5 16.25 80 1.4988 1,113 157.7 15.76 ce of ethylene or propylene glycols formed during reaction with trace water present in substrates, and also as a result other processes as described in 26. These glycols are in quantities of a few percent by weight and were isolated from oligoetherols upon distillation under reduced pressure and identified by their IR spectra. The physical properties of obtained oligoetherols, like: density, surface tension, refraction index and viscosity were measured (Table 7). These properties changed characteristically in function of temperature. It has been found that products obtained from PO have slightly lower density and refraction index in comparison with those obtained from mixture of oxiranes. The difference is probably consistent with lower packing of product due to presence of bulky methyl groups in oxyalkylene units derived from PO. Similar relationship was found in the oligoethe-rols obtained from PC. Based on the results on viscosity and surface tension it can be concluded that obtained multifunctional oligoetherols are good candidates to obtain polyurethane foams of enhanced thermal resistance. 4. Conclusions 1. The simple method of obtaining oligoetherols containing carbazole ring by two step protocol of reaction between carbazole and glycidol and futher with oxira-nes or alkylene carbonates was found. 2. Carbazole reacts with glycidol without catalyst. The process is exothermic and thus needs control of temperature. Reaction of carbazole with glycidol requires excess of glycidol, the best C:GL molar ratio is 1:7. When lower excess of GL is used, the carbazole precipitates from reaction mixture. 3. Obtained resin products (semiproducts) are soluble in oxiranes like EO and PO and in alkylene carbonates like EC and PC. Oxiranes and alkylene carbonates react with the semiproduct in presence of TEA or potassium carbonate catalysts, respectively, to give oligoetherols containing carbazole incorporated. The products are potentially useful for synthesis of polyurethane foams of enhanced thermal resistance.27 5. Acknowledgments NMR spectra were recorded within U-8689/DS 6. References 1. J. 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Lubczak, Polymer Bulletin (submitted). 23. Epoxide resins. Method of testing. Determination of the epoxide number and epoxide equivalent. Polish Standards PN-C-89085-13:1987, Ed. Polish Committee for Standar-diza-tion, 1987. 24. D. Kijowska, S. Wolowiec, J. Lubczak, J. Appl. Polym. Sci., 2004,93, 294-300. http://dx.doi.org/10.1002/app.20453 25. D. Kijowska, Przemysl Chemiczny, 2005, 84, 678-683. 26. J. Lubczak, E. Weglowska, Intern. J. Chem. Kin., 2009, 41, 523-531. http://dx.doi.org/10.1002/kin.20427 27. R. Lubczak, Cell. Polym., (in press). Povzetek V prispevku je predstavljena nova metoda sinteze multifunkcijskih oligoeterolov s karbazolnim obročem, ki so primerni za pripravo poliuretanske pene s povečano termično stabilnostjo. V prvi stopnji sinteze karbazol reagira s presežnim glicidolom, pri čemer nastane produkt z (n + 1) fukcionalnostjo, kjer n predstavlja število ekvivalentov glicidola, ki reagira s karbazolom. Vmesni produkt nadalje reagira z oksirani, kot sta etilen in propilen oksid, ali alkilen karbonati, kot sta etilen in propilen karbonat. Potek sinteze in produkte reakcije smo spremljali s klasičnimi metodami in instrumentalnimi tehnikami kot so: elementna analiza, IR, 1H-NMR in MALDI-ToF spektroskopija. V prispevku so opisane tudi nekatere fizikalno kemijske lastnosti produktov.