Garozzo, D.; Giuffrida, M.; Montaudo, G. Macromolecules 1986, 19, 1643.
Plage, B.; Schulter, H. Macromolecules 1990, 23, 2642.
Preparation of 1,1-bis(4-aminophenyl)-1-phenyl-2,2,2-trifluoroethane (3FDA). To a 1 L 3-necked round-bottomed flask equipped with a stir bar, thermocouple, Ar inlet, and Dean-Stark condenser were added 54.6 g (0.287 mol) of p-toluensulfonic acid monohydrate and 325 mL of freshly distilled amine, and the mixture was refluxed to a constant head temprature (184 °C) with separation of water. The Dean-Stark trap was replaced by a regular reflux condenser while the pot temperature was reduced to 130 °C under positive Ar pressure. At this point, 50.0 g (0.287 mol) of 2,2,2-trifluoroacetophenone was added in one portion and the mixture heated at 145 °C with stirring for 48 h. The reaction mixture was then cooled to 90 °C and 500 mL of 1 N NaOH added in one portion with vigorous stirring. After cooling to room temperature, 1 L of CH2Cl2 was added with stirring and the layers were separated. The aqueous layer was extracted with 150 mL of CH2Cl2, and the combined organic layers were washed sequentially with 4 × 250 mL of saturated NaHCO3, 4 × 250 mL of water, and 200 mL of brine. The dark solution was MgSO4, evaporated to ca. 300 mL, and added slowly to 4 L of stirring hexane. The hexane was decanted and the resulting dark semisolid taken up in about 500 mL CH2Cl2 which was again evaporated to ca. 300 mL and added slowly to 4 L of stirring hexane. The suspension was filtered to yield 78 g of a purple-red solid which was, in turn, dissolved in 2 L of (Et)2O and treated with 500 g of silica gel (60-230 mesh) and 100 g of Norit with stirring overnight. The mixture was filtered over Celite, the filtrate concentrated to ca. 125 mL, and the product slowly precipitatd with stirring into 2 L of hexane. This procedure (resuspension of the original SiO2/Norit, stirring for 1 h, filtration, and precipitation) was repeated a total of four times resulting in a total of 68 g of beige powder (subsequent treatments provide exceedingly small amounts of material). This material was taken up in 1 L of (Et)2O and treated with 50 g of silica gel and 5 g of Norit. Processing as above with precipitation into 1 L of hexane ultimately resulted in 63 g of white powder mp 215-218 °C; yield, 64%; NMR (ppm) 7.26 (m, 3H, phenyl), 7.2 (m, 2H, phenyl), 6.92 (d, 4H, aniline), 6.61 (d, 4H, aniline), 3.70 (s, 4H, NH2).
Rogers, M. E.; Mog, T. M.; Kim, Y. S.; McGrath, J. E. Mater. Plast. Soc. Symp. 1992, 164, 13.
Rogers, M. E.; Brink, M. H.; McGrath, J. E. Polymer 1983, 34, 849.
Jensen, B. J.; Hegenrother, P. M.; Ninokogu, G. Polymer 1993, 34, 639.
Preparation of 1,1-bis(4-aminophenyl)-1-(4-ethynylphenyl)-2,2,2-trifluoroethane 4-bromotrifluoroacetophenone. A 500 mL round-bottomed flask equipped with a thermometer adapter, a dropping funnel chargeed with n-butyllithium (n-BuLi) (44 mL of 1.6 M in hexane, 88 mmol; Aldrich), a second dropping funnel charged with ethyl trifluoroacetate (13.47 g, 95 mmol; Aldrich) nitrogen inlet, and magnetic stirrer was charged with 1,4-dibromobenzene (20.04 g, 85.00 mmol; Aldrich) and 150 mL of anhydrous ether (EM Science). After the 1,4-dibromobenzene dissolved, the solution was cooled to an internal temperature of -78 °C in a dry ice/acetone bath. The n-BuLi was added dropwise over a period of 30 min, and the reaction mixture was allowed to stir at -78 °C for 2 h. The mixture was then allowed to warm to 0 °C and then recooled to -78 6C before the ethyl trifluoroacetate was added dropwise. Then the mixture was allowed to warm to room temperature overnight. The mixture was then cooled to -25 °C, and 40 mL of saturated aqueous ammonium chloride (EM Science) was added dropwise followed by 40 mL of 1 N hydrochloric acid. The mixture was allowed to warm to room temperature. The reaction mixture was transferred to a separatory funnel, and the aqueous layer was removed. The ether layer was washed with 100 mL of saturated aqueous sodium bicarbonate (NaHCO3), dried over anhydrous magnesium sulfate (MgSO4), filtered, and rotary evaporated to remove the solvent. The oil was vacuum distilled and a water white liquid was distilled over a 45 °C at 900 μmHg. This liquid solidified to 19.21 g of 4-bromotrifluoroacetophenone, a white solid (89% yield). Proton NMR in deuterated chloroform shows an AB quartet centered at 7.83 ppm. Preparation of 1,1-bis(4-aminophenyl)-1-(4-bromophenyl)-2,2,2-trifluoroethane. 4-Bromotrifluoroacetophenone (19.14 g, 75.65 mmol), aniline hydrochloride (13.18 g, 101.7 mmol, recrystallized; Aldrich), and aniline (53.3 mL, 62.87 mmol, distilled, Aldrich) were placed in a 250 mL round-bottomed flask and refluxed (120-133 °C) under nitrogen for 24 h. After cooling to room temperature, NaHCO3 (17.2 g) and water were added, and the aniline and water were codistilled off molar nitrogen until no further aniline was observed in the distillate. After cooling again, the water was decanted off, and the purple solid was dissolved in chloroform (200 mL). The solution was dried over anhydrous MgSO4 and then filtered through silica gel using acetone and methylene chloride to wash the silica gel. The solvent was rotary evaporated to yield a purple oil which was dried further in a 60 °C vacuum oven to yield 31.5 g of a purple semisolid (99% yield). Proton NMR in deuterated chloroform shows two AB quartets centered at 7.25 (4H) and 6.75 (8H) ppm and a broad singlet at 3.72 ppm (4H). Preparation of 1,1-bis(4-aminophenyl)-1-(4-ethynylphenyl)-2,2,2-trifluoroethane. 1,1-Bis(4-aminophenyl)-1-(4-bromophenyl)-2,2,2-trifluoroethane (31.5, 74.77 mmol) was dissolved in a mixture of triethylamine (125 mL, distilled) and N-methylpyrrolidinone (NMP) under an atmosphere of argon. Copper(I) iodide (0.33 g, 1.73 mmol; Aldrich), tetrakis(triphenylphosphine)palladium(0) (2.08 g, 1.80 mmol; Aldrich), and (trimethylsilyl)acetylene (14.56 g, 148.24 mmol; Farchan) were then added. The flask was sealed with a septum, stirred with a magnetic stirrer, and heated in a 90 °C oil bath for 24 h. After cooling to room temperature, the solvents were removed on a rotary to evaporator. The solids were triturated with ether and filtered off. The ether solution was washed with water (3 × 250 mL), dried over MgSO4, filtered, and rotary evaporated to a brown solid. Ethanol (250 mL) and 1 N sodium hydroxide (50 mL) were added, and the mixture was stirred at room temperature overnight, transferred to a separatory funnel, added to ether (500 mL), and washed twice with water. It was then dried over MgSO4 and filtered, and the solvent was rotary evaporated off. The sample dried in a 60 °C vacuum oven to yield 16.8 g of a light brown foamy solid (61% yield). Proton NMR in deuterated chloroform shows two AB quarters at 7.35 (4H) and 6.8 (8H) ppm and broad singlets at 3.76 (4H) and 1.67 (1H) ppm.
To a 250 mL 3-necked round-bottomed flask equipped with a stir bar, thermocouple, and Ar inlet were added 19.5 g (1.95 mmol) of 10K poly(∈-caprolactone), 100 mL of anhydrous THF, and 0.232 g (2.925 mmol) of pyridine. The mixture was cooled to 5 °C under Ar, and 0.59 g (2.925 mmol) of 4-nitrophenyl chloroformate dissolved in 10 mL of THF was added dropwise. The temperature was allowed to each ambient and the mixture stirred for 48 h. The resulting suspension was filtered, and the filtrate was evaporated. The residue was dissolved in a minimum amount of CH2Cl2 and precipitated into 500 mL of stirring methanol. The solid was filtered, washed with methanol, and air-dried. The resulting white powder (17.5 g) was taken up in 100 mL of anhydrous THF, charged into a Paar hydrogenation bottle containing 750 mg of Pd(OH)2 (Pearlman's catalyst), and hydrogenated at 40 psi for 48 h. The reaction mixture was filterd twice through a Celite pad, evaporated, redissolved in 300 mL of CH2Cl2, and washed with 2 × 100 mL of saturated NaHCO3 followed by 2 × 100 mL of water. The organic layer was reduced to ≈65 mL and added slowly to 500 mL of methanol with vigorous stirring. The resulting solid was collected and dried for 48 h at 40 °C under reduced pressure to yield 13.5 g of the desired product as a white powder. Titration of the amine end group yielded a molecular weight of 10 500 g/mol.
Volksen, W.; Yoon, D. Y.; Hedrick, J. L.; Hofer, D. Mater. Res. Soc. Symp. Proc. 1991, 227, 23.
The amic ester-α-caprolactone triblock copolymers were prepared by the coreaction of the amino-terminated caprolactone oligomers with 3FDA, 3FET, and PMDA diethyl ester diacyl chloride in NMP in the presence of N-methylmorpholine. A detailed procedure designed to prepare an amic ester-α-methylstyrene copolymer, having a caprolactone content of 25 wt %, using a caprolactone olgiomer of 10 000 g/mol molecular weight is provided (copolymer 3, Table 1). A 3-necked flask equipped with an overhead stirrer and addition funnel was charged with caprolactone olgiomer (1.0000 g, 0.000 095 2 mol), 3FDA (0.913 27 g, 0.000 266 7 mol), and 3FET (0.6515 g, 0.001 778 mol) and carefully rinsed in with 15 mL of NMP. The solution was then cooled to -5 °C, and pyridine (0.710 00 g, 0.008 90 mol) was added to the solution. The PMDA diethyl ester diacyl chloride (1.5600 g, 6.004 490 mol) was dissolved in ca. 25 mL of methylene chloride and added in increments over a 2 h period so as to slowly approach the stoichiometric end point. The polymerization was allowed to proceed overnight and the mixture isolated by precipitation in methanol/water, rinsed with water (to remove excess salts) and cyclohexene (to remove possible homopolymer contamination), and dried in a vacuum oven.
Isothermal and variable temperature (5 °C min-1 heating rate) thermal gravimetric analysis (TGA) measurements were performed on a Perkin-Elmer model TGA-7 instrument in a nitrogen atmosphere.
Sanchez, M. I.; Hedrick, J. L.; Russell, T. P. J. Polym. Sci., Part B: Polym. Phys. 1995, 33, 253.
