Vacuum-dried copolymers

The mash from the Streptomyces aureofaciens fermentation broth is acidified and filtered. The filtrate is adjusted to the desired pH, usually 7-8.5, and various flocculating or chelating agents may be added (e.g., vinyl acetate-maleic anhydride copolymer, sodium EDTA, ammonium oxalate, Arquad). The precipitate is (1) stirred with filter aid, filtered, stirred with HC1, refiltered, mixed with 2-ethoxyethanol, filtered, washed, and the filtrates are combined, acidified with HC1, NaCl is added, and the crystals are collected, washed with 2-ethoxyethanol, water, and ethanol, and dried (67), or (2) extracted into methyl isobutyl ketone, the extracts are combined, filtered, and acidified with HC1, and the crystals are collected and washed with water, 2-ethoxyethanol, and isopropanol, and vacuum-dried. If the crystals are greenish, they are treated with sodium hydrosulfite at pH 1.8, filtered, washed, and dried as in (1) above (68). 

A flask was charged with 1-(1,1-dimethyl-2,2-ditrifluoromethyl-2-hydroxyl)ethyl methacrylate (176.46 g), l-(l-cyclohexyl-2,2-ditrifluoromethyl-2-hydroxyl)ethyl methacrylate (23.54 g), dimethyl 2,2 -azobisisobutyrate (3.74 g), and isopropyl alcohol (100.0 g) and then cooled to 20-25°C. In a separate flask isopropyl alcohol (50.0 g) was heated to 80°C and then added dropwise to the monomer solution over 4 hours and then stirred for 3 hours at 80°C. The solution was then cooled to ambient temperature and then precipitated in 4 liters of water and then isolated. The copolymer was washed four times with 600 g of isopropyl ether/hexane, 9 1, respectively, and a white solid isolated. After vacuum drying 90.1 g of the product was isolated having an Mw of 9600Da with a polydispersity of 1.6 and consisting of 80/20mol% 1-(l,l-dimethyl-2,2-ditrifluoromethyl-2-hydroxyl) ethyl methacrylate and l-(l-cyclo-hexyl-2,2-ditrifluoromethyl-2-hydroxyl)ethyl methacrylate, respectively. 

To a methyl ethyl ketone solution of =Si—H containing polymers or copolymers, a cold solution (ca. -10 °C) of dimethyldioxirane in acetone was quickly added and reacted for 30 min at 0 °C. The mole ratio of dioxirane to polymer was ca. 1.2 1.3. The resulting silanol polymers or copolymers were obtained either in solution or precipitated into hexanes followed by vacuum dry at 40 °C for 24 h. 

The butadiene (80%)-acrylonitrile(17%)-aerylamidoxime(3%) terpolymer was prepared by reacting 2.5g butadiene 80%)-acrylo-nitrile(20%) copolymer (Aldrich) in 150 ml xylene with 1.61g hydro-xylamine hydrochloride in 12 ml n-butanol (freed of HC1 immediately before addition by method of Hurd (4) by dropwise addition under nitrogen. Reaction time and temperature were 23 hr. and 90-95°C. The polymer product was worked up by slowly adding the reaction mixture to 500 ml ether with rapid stirring. The precipitated polymer was allowed to settle, the supernate decanted and the polymer resuspended and washed with two 100 ml portions of ether followed by vacuum drying. Yield 2.04g (81%). Conversion of nitrile functional groups to amidoxime groups was 15% by infrared absorption. 

A similar procedure was used to prepare starch-j -polyacrylamlde, and 15 g of acrylamide (97%, Polysciences) was used In the polymerization. After irradiation, the reaction mass was extracted several times with water to remove ungrafted polyacrylamide, and the graft copolymer was washed with ethanol and vacuum dried at 60°C. Weight percent polyacrylamide in the graft copolymer (% add-on) was 35%, based on the weight gain of starch. 

The quenched reaction mixture is diluted with 20 mL of toluene and washed with 10 w/v% aqueous sodium thiosulfate solution (20 mL x 3) and then with deionized water (20 mL x 2), evaporated to dryness (30° C ca. 40 Torr), and vacuum dried overnight to give the AcOVE-IBVE block copolymer in almost quantitative yield the AcOVE/IBVE mole ratio in the polymer ( H NMR) = 30 9, being close to the initial feed ratio of the two monomers. 

Stirred solutions of each polymer or copolymer at a concentration of 10 mg./ml. were irradiated in air at 25°C in a quartz vessel with the light from a low-pressure mercury lamp at an absorbed intensity of 2.95 x 10 quanta ml sec. . Polymer films, evaporated from DMM or methylene chloride solutions on quartz cuvettes or plates and vacuum dried, were irradiated in air at about 35°C in a Rayonnet Model RPR-100 Photochemical Reactor containing 12 low-pressure mercury lamps the incident radiation at the films was 1.3 x 10 quanta cm" sec"l. 

CL-AGE copolymer films of ca. 3-mil-thickness were additionally vacuum-dried for 48 hours. Two sample temperatures, 25°C(semi-crystalline state) and 80°C(melt state), were utilized for irradiation. For the higher temperature of 80°C, a heated steel plate was used as the substrate for the copolymer. The film sample was placed on this temperature-controlled steel plate and passed through the electrocurtain system described below. For the irradiation process which required two passes, following the first pass the sample was again immediately placed on another 80 C steel plate and passed through the electrocurtain system a second time. 

Random copolymers of acrylamide with N,N-dimethylacrylamide and with N,N-diethylacrylamide were prepared as illustrated in reactions (7) and (8). The respective copol3nners, PAMDMAM and PAMDEAM, have been synthesized to elucidate more fully the role of hydrogen-bonding and N-substitution on viscosity modification. These polymers were synthesized using potassium persulfate initiators in water or 30% methanol/water solutions. Reaction conditions and monomer feed ratios are given in Table 2. The resulting copolymers were purified by precipitation into acetone followed by vacuum drying at 50 C for 60 hours. 

The graft copolymer thus obtained was extracted with cyclohexane three times, each for 24 hours, so as to remove unreacted polystyrene. After vacuum drying, it was extracted three times (each lasting 24 hrs) with 20% aqueous solution of ethyl alcohol, in order to remove polyoxyethylene homopolymer. Phenyl content of the graft copolymer and the extracts were measured by a 730 Ultraviolet Spectrophotometer. IR spectra were obtained by a Perkin-Elmer 580B Spectrophometer. 

Thus, to a dry, round bottom, two neck flask, 95 grams of p-dioxanone, 0.197 ml of 1-dodecanol, and 0.0975 ml of stannous octoate (0.33 molar in toluene) are added. The stirred reaction mixture is heated under nitrogen for 6 hours at 100 C. Five grams of L(-) lactide are added to the reaction mixture, and the temperature is raised to 140°C and maintained there for 2 hours. The copolymer is isolated, ground, and vacuum dried for 48 hours at 80°C. 

Two copolymers, a poly(styrene-6-isoprene-7>-styrene) (SIS) triblock (60 wt% S Mn=100,000, Mw/Mn=1.04) and a poly(styrene-Wsoprene) (SI) diblock (70 wt% S Mn=50,000, Mw/Mn=1.05), were synthesized by anionic polymerization. The selective solvent used here was an aliphatic white mineral oil (MO) produced by Witco (380PO). Specific masses of each copolymer and MO weae dissolved in cyclohexane and cast into molds. Upon solvent evaporation, the resultant films were vacuum-dried for up to 7 h at 120 C. Steady-shear tests were performed on a Rheometrics dynamic stress rheometer (DSR) as a function of shear stress (x) to measure the solution viscosity (q), while dynamic tests were performed here to discern G and G" as functions of x, oo and temperature. 

The poly(glycolide-co-caprolactone) (PGCL) copolymer was mainly synthesized by the ringopening polymerization. A copolymer with 1 1 mole ratio was synthesized by the ring-opening polymerization in the presence of the catalyst Sn(Oct)2 by Lee and coworkers. The polymerization was under vacuum, and heated in an oil bath at 170°C for 20 h. The copolymer was then dried under vacuum at room temperature for 72 h. The schematic reaction equations are shown in Schemes 8.5 and 8.6. 

Prior to imide formation, the imide-aryl ether ketimine copolymers were converted to the imide-aryl ether ketone analogue by hydrolysis of the ketimine moiety with para-toluene sulfonic acid hydrate (PTS) according to a literature procedure [51,52,57-59]. The copolymers were dissolved in NMP and heated to 50 °C and subjected to excess PTS for 8 h. The reaction mixtures were isolated in excess water and then rinsed with methanol and dried in a vacuum oven to afford the amic ester-aryl ether ether ketone copolymer, 2e (Scheme 8.)... 

Method D in Table 1 represents a case where dry support films were always used because of the need to employ a vacuum and because of the very nature of plasma deposition processes. Yasuda (12) showed that a wide variety of gas phase reactants could be used in this technique. Not only conventional vinyl monomers were used but also any organic compounds with adequate vapor pressure. Further, copolymers could be prepared by introduction of a second reactant such as nitrogen. Wydeven and coworkers (13,14) showed the utility of this method in preparing reverse osmosis membranes from an allylamine plasma. 

The precipitate was filtered off, washed with ether, and dried under vacuum to yield 4.7 g of dry product (A-poly-2). Thin layer chromatography on silica gel using dichloromethane/methanol (93 7) showed only a trace of free monomer. This activated copolymer was soluble in water, THF, CH2CI2 and DMF. It was reproducibly prepared in good quantity and stored in the solid state for months, protected from moisture, without loss of activity. 

A100 ml flask is fitted with an adapter (see Sect. 2.2.5.3), flamed under vacuum using an oil pump, and filled with nitrogen. 5 ml of the prepared monomer mixture (see above) are pipetted in, followed by 40 ml of an initiator solution prepared from 50 ml of pure dry nitrobenzene (see Example 3-40) and 300 mg (2.25 mmol) of anhydrous aluminum trichloride.The flask is now removed from the adapter under a slight positive pressure of nitrogen and immediately closed with a ground glass stopper.The flask is briefly shaken and allowed to stand at room temperature for 1 h.The solution is then dropped into methanoi and the copolymer worked up as described above. Yield 40-50% with respect to the monomer mixture. 

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