Article pubs.acs.org/Macromolecules
Sustainable Polyester Resins Derived from Rosins Guerino G. Sacripante,* Ke Zhou, and Muntaser Farooque Xerox Research Centre of Canada, Mississauga, Ontario, Canada L5K 2L1 S Supporting Information *
ABSTRACT: Renewable dehydroabietic acid was functionalized to predominantly a rosin-diol and bis-rosin alcohol mixture by reaction with glycerin carbonate and tetraethylammonium iodide. The corresponding adducts were subsequently polymerized with a variety of organic diacids to provide thermoplastic resins with a variety of thermal properties. Optimization of the copolyester composition with selected diacid(s) and diol(s) provided a suitable resin with the required thermal and rheological properties for use as xerographic toners.
■
INTRODUCTION Over the past decade, considerable progress has been made to replace petroleum-based polymers with sustainable materials from renewable biomass feedstock. The most prevalent commercial bio-based polymers1 are polyurethanes and polyester, obtained from bio-based monomers such as propanediol, butanediol, succinic acid, lactic acid, and dimer acids (and diols) derived from corn-, sugar-, or plant-based oils. However, these sources are food-based, and critics have suggested more sustainable monomers from non-food biomass, especially those from the forestry byproduct such as from lignocellulose or resenic acids obtained from pulp byproduct (tall oil), gum, or wood rosins. Although there are still challenges to degrade or transform lignocellulose to economical bio-based monomer, the latter resenic acids (Scheme 1) are
abietic, neoabietic, plausteric, and levopimaric acids can be converted to useful polyfunctional condensation type monomers such as the rosin diacid or triacid utilizing acrylic acid,3 fumaric acid, or maleic anhydride.4 Polyesters from these have been explored5−7 but require purification of the polyfunctional rosin acid from the other rosin acids. Disproportionation (aromatization) of the rosin acid mixture in the melt with catalyst can yield >90% of dehydroabietic acid. Dimerization of the dehydroabietic acid with variety of linkages has been reported by Sakumo and Sato8 to result in a bis-rosin diacid with subsequent polymerization with glycols to yield polyester. However, the bis-rosin diacid formation is solvent based with poor yields and difficult to economically compete with petroleum-based polymers. The resenic acid mixture can also be economically hydrogenated, yielding mostly tetrahydroabietic acid together with dehydroabietic acid mixture. Both disproportionation and hydrogenation result in a more thermally stable rosin acid material to prevent from auto-freeradical polymerization. Polymerization of the dehydroabietic acid through the functional carboxylic acid has been reported by esterification of dehydroabietic acid moiety to an acrylate followed by radical polymerization9 or by reacting with petroleum-based bis-epoxide to yield the diol followed by condensation polymerization with organic diacids.10,11 Herein, we would like to report a simpler and more economical method of functionalizing the rosin acid to predominantly a rosin-diol derivative, followed by condensation polymerization with diacid/diol(s) to polyester resins for xerographic toner application.
Scheme 1. Resenic Acids (or Rosin Acids)
■
easily extracted, inexpensive, and sustainable with worldwide production in excess of 1.2 million tons annually (mostly from China and Brazil). Promoting demand of resenic acids, especially in Brazil, would also encourage less deforestation of the Amazon which represents almost 20% of earth’s oxygen production. The resenic (or rosin) acid mixture (Scheme 1) is mainly composed of the abietic acid depending on its source.2 The © XXXX American Chemical Society
EXPERIMENTAL SECTION
Materials. Bio-based succinic acid (>99.5%) was obtained from Bioamber, terephthalic acid (>99.5%) was obtained from Invista, biobased furan-2,5-dicarboxylic acid (>99%) was obtained from Ubichem Received: July 3, 2015 Revised: September 2, 2015
A
DOI: 10.1021/acs.macromol.5b01462 Macromolecules XXXX, XXX, XXX−XXX
Article
Macromolecules Fine Chemicals, bio-based 1,2-propylene glycol (>99%) was obtained from Archer Daniels Midland Company, and disproportionate rosin mainly composed of dehydroabietic acid (>90%) was obtained from Arakawa Chemicals (Japan), with an acid value (AV) of 163.6 mg of KOH/g. Higher purity of the dehydroabietic acid (AV = 175.6 6 mg of KOH/g) was obtained by a published procedure12 (>97%). Titanium bis(triethanolamine) bis(isopropoxide) was obtained from Matsumoto Fine Chemicals (Japan) as Orgatix TC-400 (85% in isopropanol). Glycerin carbonate (>93.5%) was obtained from Huntsman and redistilled using a thin film evaporator to >96% purity (GLC). Ethylene carbonate (>99%) was also obtained from Huntsman and used as received. TLC aluminum oxide 60 F254 (neutral) sheets were obtained from Merck KGaA. Ethyl acetate, methyl ethyl ketone, isopropanol, tetrahydrofuran (THF), hexanes, and sodium bicarbonate were obtained from Caledon Laboratories. Anhydrous ethyl ether, anhydrous copper(II) chloride, tetraethylammonium iodide, aluminum sulfate, sodium hydroxide, CDCl3, phenolphthalein indicator, and 0.1 N potassium hydroxide in methanol were obtained from SigmaAldrich and used as received. The polyethylene wax aqueous dispersion (D-1479) was obtained from Baker Petrolite. The cyan aqueous cyan pigment dispersion was obtained as PB15:3 from SUN Chemicals. Characterization. 1H and 13C NMR spectra were recorded on Bruker Ascend 400 spectrometer. The chemical shifts were recorded in ppm (δ) relative to tetramethylsilane. Gel permeation chromatography (GPC) was performed using a Waters APC 2695 equipped with a refractive index detector and using polystyrene as standards. Thermal transitions were recorded using the TA Instruments Q1000 differential scanning calorimeter in a temperature range from 0 to 150 °C at a heating rate of 10 °C/min under nitrogen flow. The melting and glass transition temperatures were collected during the second heating scan and reported as the onset. Acid values (AV) were measured by the ASTM D 974 method using 0.5 g of test material dissolved in THF with 2−3 drops of phenolphthalein as indicator and 0.1 N potassium hydroxide (KOH) in methanol as the titrant. Elemental analysis was done using a LECO TrueSpec Micro CHNS and TruSpec Micro Oxygen analyszer. Mass spectroscopy was obtained using Waters Alliance Q-T MS. Infrared spectroscopy was obtained using the Bruker Alpha-P FT-IR spectrometer and an ATR sampling module with 4 cm−1 resolution. Particle size measurement was obtained utilizing the Multisizer 3 Coulter Counter available from Beckman Coulter. Scanning electron microscopy (SEM) was performed utilizing a Hitachi SU8000 SEM. Synthesis. Preparation of 2′-Hydroxyethyl Dehydroabietate (3). To a 1 L Parr 4020 reactor equipped with a mechanical stirrer was added ethylene carbonate, 1 (92.4 g, 1.05 mol), tetraethylammonium iodide (1.285 g, 0.005 mol), and dehydroabietic acid (300.4 g, 1 mol) with an acid value of 175.6 mg of KOH/g. The mixture was heated to 160 °C under a nitrogen atmosphere for 6 h and until an acid value of 99% conversion). The yellow viscous liquid product was then purified by chromatographic separation using ethyl acetate (15%) and hexanes (85%) as eluent to result in colorless viscous oil. 1H NMR (400 MHz, CDCl3, δ): 7.18 (d, J = 4 Hz, 1H); 7.01 (d, J = 4 Hz, 1H); 6.89 (s, 1H); 4.15−4.28 (m, 2H); 3.81 (t, J = 4 Hz, 2H); 2.79 (m, 2H); 2.75−2.86 (m, 1H); 2.25− 2.33 (dd, J = 12, 12 Hz, 2H); 1.66−1.90 (m, 6H); 1.42−1.51 (m, 2H), 1.30 (s, 3H); 1.24 (s, 3H); 1.22 (s, 6H). 13C NMR (400 MHz, CDCl3, δ): 179.0 (C18); 146.8 (C9), 145.8 (C13), 134.6 (C8), 127 (C14), 124.2 (C12), 124 (C11); 66.3 (C1′); 61.5 (C2′); 47.8 (C4), 44.9 (C5), 38 (C1), 37 (C10), 36.7 (C3), 33.5 (C15), 30.1 (C7), 25.2 (C20), 24.0 (C16, C17), 21.8 (C6) 18.6 (C2), 16.5 (C19). The assignment of the carbon signals was made on the basis of DEPT experiment. MS: m/z calculated for C22H32O3: 344.49; found: 345.22. Elemental analysis calculated for C22H32O3: 76.7% C; 9.36% H; 13.93% O; found: 77.6% C; 9.38% H; 14.31% O. Preparation of 2′,3′-Dihydroxypropyl Dehydroabietate (4), 1′,3′Dihydroxypropyl 2′-Dehydroabietate (5), 2′,3′-Dioxalan-4′-one Dehydroabietate (6), 1′,2′-Didehydroabietate-3-hydroxypropane (7), and 1′,3′-Didehydroabietate-2′-hydroxypropane (8). General procedure (see first entry of Table 1): To a 1 L Parr 4020 reactor
Table 1. Reaction Products from Dehydroabietic Acid and Glycerin Carbonate rosin adduct (%) temp (°C)
catalyst (mol %)
4/5
6
7
8
ratio 4/5/6:7/8
150 165 150 165
0.5 0.5 18 18
63.5 44.0 61.9 56.0
14.7 15.2 12.5 9.29
13.7 21.3 12.4 12.0
5.7 17.5 5.3 8.14
4.03:1 1.52:1 4.20:1 3.24:1
equipped with a mechanical stirrer was added glycerin carbonate 2 (130 g, 1.1 mol), tetraethylammonium iodide (1.285 g, 0.005 mol), and dehydroabietic acid (100.1 g, 0.33 mol) with an acid value of 175.6 mg of KOH/g. The mixture was heated to 150 °C under a nitrogen atmosphere, and after 2 h, dehydroabietic acid (200.3 g, 0.67 mol) was added slowly over a 2 h period. The temperature was maintained at 150 °C for an additional 8 h and until an acid value of 99%) conversion. The product was discharged as a yellow-brownish viscous liquid, dissolved in ethyl acetate, and extracted two times with dilute sodium bicarbonate aqueous solution, and the organic portion was rotary evaporated to result in a yellow viscous solid. The reaction products were subjected to high pressure chromatographic separation using ethyl acetate (25%) and hexanes (75%) as eluent. Compounds 6, 7, and 8 were cleanly separated, but the products 4 and 5 could not be separated by chromatography and obtained as viscous oil. The products 4 and 5 were separated by dissolving 1 g of the mixture in 40 mL of diethyl ether, followed by the addition of 0.4 g of copper(II) chloride under nitrogen. The mixture turned yellowish-brown and formed a crystalline precipitate. The crystalline precipitate was filtered off and washed with small amount of ether. The solid was then dissolved in 40 mL of acetone and treated with gaseous ammonia and evaporated to give a viscous colorless oil of 4. The ether filtrate from above was filtered through a short pad of silica and evaporated off to give a viscous pale yellow oil composed of rosin-diol 5 together with rosin-diol 4. Partial isolation of the rosindiol 5 from 4 was achieved using aluminum oxide (neutral) TLC sheets with a solvent mixture of 70% ethyl acetate and 30% hexane to give 5 as a colorless oil. 2′,3′-Dihydroxypropyl dehydroabietate (4) was obtained as a colorless viscous oil. 1H NMR (400 MHz, CDCl3, δ): 7.18 (d, J = 4 Hz, 1H); 7.02 (d, J = 4 Hz, 1H); 6.9 (s, 1H); 4.11−4.22 (m, 2H); 3.89 (bs, 1H); 3.65 (bm, 1H); 3.58 (bm, 1H); 2.83−2.9 (m, 4H); 2.23−2.33 (dd, J = 12, 12 Hz, 2H); 1.68−1.91 (m, 6H); 1.41−1.53 (m, 2H); 1.30 (s, 3H); 1.24 (s, 3H); 1.22 (s, 6H). 13C NMR (400 MHz, CDCl3, δ): 179.2 (CO2); 146.7 (C9), 145.8 (C13), 134.5 (C8), 127 (C14), 124.2 (C12), 124 (C11); 70.4 (C1′); 65.4 (C2′); 63.4 (C3′); 47.9 (C4), 44.9 (C5), 37.9 (C1), 37 (C10), 36.8 (C3), 33.5 (C15), 30.1 (C7), 25.2 (C20), 24.0 (C16, C17), 21.8 (C6) 18.6 (C2), 16.6 (C19). The assignment of the carbon signals was made on the basis of DEPT experiment. MS: m/z calculated for C23H34O4: 374.25; found: 374.1. Elemental analysis calculated for C23H34O4: 73.76% C; 9.15% H; found 73.2% C; 9.04% H. 1′,3′-Dihydroxypropyl 2′-dehydroabietate (5) was obtained as a colorless viscous oil. 1H NMR (400 MHz, CDCl3, δ): 7.17 (d, J = 4 Hz, 1H); 7.01 (d, J = 4 Hz, 1H); 6.89 (s, 1H); 4.92−4.95 (m, 1H); 3.81 (bs, 4H). 2.81−2.9 (m, 3H); 2.25−2.33 (dd, J = 12, 12 Hz, 2H); 1.70− 1.90 (m, 8H); 1.44−1.60 (m, 2H); 1.30 (s, 3H); 1.23 (s, 3H); 1.21 (s, 6H). 13C NMR (400 MHz, CDCl3, δ): 178.7 (CO2); 146.7 (C9), 145.9 (C13), 134.5 (C8), 127 (C14), 124.2 (C12), 124.1 (C11); 75.2 (C2′); 62.7 (C1′, C3′); 48 (C4), 45 (C5), 37.9 (C1), 37.0 (C10), 36.7 (C3), 33.5 (C15), 30.2 (C7), 25.2 (C20), 24.0 (C16, C17), 21.8 (C6) 18.6 (C2), 16.6 (C19). The assignment of the carbon signals was made on the basis of DEPT experiment. MS: m/z calculated for C23H34O4: 374.25; found: 374.2. 2′,3′-Dioxalan-4′-one dehydroabietate (6) was obtained as colorless crystals. Alpha-P FT-IR neat (cm−1): 2933, 1791 (s, CO3), 1724 (s, CO2), 1385, 1239, 1166, 1088, 1051. 1H NMR (400 MHz, CDCl3, δ): 7.16 (d, J = 4 Hz, 1H); 7.01 (d, J = 4 Hz, 1H); 6.89 (s, 1H); 4.89−4.94 B
DOI: 10.1021/acs.macromol.5b01462 Macromolecules XXXX, XXX, XXX−XXX
Article
Macromolecules (m, 1H); 4.35−4.58 (m, 2H); 4.23−4.29 (m, 2H); 2.78−2.91 (m, 3H); 2.315 (d, J = 12, 1H); 2.215 (dd, J = 4, 12 Hz, 1H); 1.74−1.87 (m, 5H); 1.36−1.53 (m, 2H); 1.37 (s, 3H); 1.24 (s, 3H); 1.22 (s, 6H). 13 C NMR (400 MHz, CDCl3, δ): 178.0 (C18); 154.3 (C4′) ;146.6 (C9), 145.8 (C13), 134.5 (C8), 126.9 (C14), 124.1 (C12, C11); 73.8 (C2′); 66.0 (C3′); 63.2 (C1′); 48 (C4), 45 (C5), 37.8 (C1), 37 (C10), 36.7 (C3), 33.5 (C15), 30.0 (C7), 25.2 (C20), 24.0 (C16, C17), 21.9 (C6) 18.5 (C2), 16.4 (C19). The assignment of the carbon signals was made on the basis of DEPT experiment. IR MS: m/z calculated for C23H34O4: 400.2; found: 401.1. Elemental analysis calculated for C24H32O5: 71.97% C; 8.05% H; found 71.92% C; 8.20% H. 1′,2′-Didehydroabietate-3′-hydroxypropane (7) was obtained as colorless crystals. 1H NMR (400 MHz, CDCl3, δ): 7.12 (bm, 2H); 7.00 (bd, 2H); 6.88 (bs, 2H); 5.05−5.11 (m, 1H), 4.19−4.35 (m, 2H); 3.68−3.71 (m, 2H); 2.82−2.84 (m, 6H); 2.15−2.26 (m, 4H); 1.52− 1.92 (m, 12H), 1.42−1.5 (m, 4H), 1.18−1.25 (m, 24H). 13C NMR (400 MHz, CDCl3, δ): 178.5 (C18″), 178.0 (C18), 146.7, 145.7, 134.5, 126.9, 124.2, 124.1, 124, 72.6, 72.3 (C2′), 62.5 (C1′), 61.6 (C3′), 47.8, 44.8, 44.8, 36.9, 36.7, 33.5, 30.2, 30.1, 25.2, 24, 21.8, 18.5, 16.5. MS: m/z calculated for C43H60O5: 656.44; found: 656.1. Elemental analysis calculated for C43H60O5: 78.62% C; 9.21% H; found 79.2% C; 9.05% H. 1,3-Didehydroabietate-2-hydroxypropane (8) was obtained as colorless crystals with melting point of 171.8 °C (DSC). 1H NMR (400 MHz, CDCl3, δ): 7.16 (d, J = 4 Hz, 2H); 7.0 (d, J = 4 Hz, 2H); 6.88 (s, 2H); 4.10−4.20 (m, 4H); 4.03−4.10 (m, 1H); 2.79−2.88 (m, 6H); 2.37 (d, J = 4 Hz, 1H); 2.21−2.32 (dd, J = 12, 12 Hz, 4H); 1.65−1.90 (m, 10H); 1.40−1.54 (m, 4H); 1.29 (s, 6H), 1.23 (s, 12H), 1.21 (s, 9H). 13 C NMR (400 MHz, CDCl3, δ): 178.7 (CO2); 146.7 (C9), 145.8 (C13), 134.6 (C8), 127 (C14), 124.2 (C12), 124.0 (C11); 68.7 (C2′); 65.4 (C2′); 47.9 (C4), 44.9 (C5), 37.9 (C1), 37 (C10), 36.7 (C3), 33.5 (C15), 30.1 (C7), 25.2 (C20), 24.0 (C16, C17), 21.8 (C6) 18.6 (C2), 16.6 (C19). The assignment of the carbon signals was made on the basis of DEPT experiment. MS: m/z calculated for C43H60O5: 656.44; found: 655.0. Elemental analysis calculated for C43H60O5: 78.62% C; 9.21% H; found 78.7% C; 8.92% H. Preparation of 1′,2′,3′-Tridehydroabietatepropane (9). To a 1 L Parr 4020 reactor equipped with a mechanical stirrer was added glycerin carbonate (130 g, 1.1 mol), tetraethylammonium iodide (2.57 g, 0.01 mol), and dehydroabietic acid (901.2 g, 3.0 mol) with an acid value of 175.6 mg of KOH/g. The mixture was heated to 165 °C for 8 h, followed by heating to 210 °C over a 2 h period, followed by heating to 240 °C over a 2 h period, and then heated to 275 °C over a 2 h period and maintained at 275 °C for an additional 8 h, and until the acid value was
