Butyl acrylate, dilute solution

For polystyrene fractions in diethyl phthalate solution (30000average value of 1.6 x 10 18 ( 50%). In dilute solution e/36M is 1.27 x 10 18 for polystyrene (21). No systematic variations with concentration, molecular weight or temperature were apparent, the scatter of the data being mainly attributable to the experimental difficulties of the diffusion measurements. The value of Drj/cRT for an undiluted tagged fraction of polyfn-butyl acrylate) m pure polymer was found to be 2.8 x 10 18. The value of dilute solution data for other acrylate polymers (34). Thus, transport behavior, like the scattering experiments, supports random coil configuration in concentrated systems, with perhaps some small expansion beyond 6-dimensions. 

A copolymer of butyl acrylate and acrylic acid was synthesized so as to approximate formulations used in waterborne formulation practice without departing drastically from the acrylic acid homopolymer. When 2-methy1-2-propanol solutions of these polymers were diluted with water and then dried, the rigidity trends followed the pattern (72) shown in Figure 8 and no evidence of secondary hydration was present. Reference to the original articles will reveal that the number of carboxylate triads should be minimized in the copolymerization if one wishes to ensure that the marketed product will be water insensitive. 

The kinetics of dilute solution polymerization of butyl acrylate were studied by Melville and Bickel (15). They measured the propagation and termination coefficients at 25 c kp 13(i/mole sec) and kt 1.8 x 10 ( /mole sec). Melville and Bickel also concluded that the termination reaction at 25 C occurred mostly throu combination, thus theoretically increasing the probability to produce a carboxyl terminated PnBA with an ideal ftuiction-allty of f=2 when the polymerization reaction is initiated with ABCVA. 

Polymerization of CTPnBA in dilute solution. The solution polymerization of N-butyl acrylate is better predicted and simpler to control. The effect of the molecular weight on the miscibility of CTPnBA in Epon 828 was studied with a series of polymers polymerized in dilute t-butanol solutions. Table I. As expected. Increasing both dilution of the monomer and the polymerization temperature resulted in decreasing molecular weight of CTPnBA. 

The study of the toughening of DGEBA resin with a new RLP, Carboxyl Terminated n-Poly Butyl Acrylate (CTPnBA), is reported here. The CTPnBA rubber was synthesized by dilute solution polymerization and bulk polymerization techniques (20,21). The carboxyl functionality of the polymers varied from f = 1.3 (in solution polymerization) to f = 1.8-2.0 (in bulk polymerization). 

A mixture consisting of the step 2 product (40 g), potassium bicarbonate (48.7 g), tetra-butylammonium iodide (8.0 g), 2,6-di-ter -butyl-4-mcthylphcnol (1.74 g), and 500 ml THF was treated with acrylic acid (11.2 g) and then refluxed for 6.5 hours and stirred at ambient temperature for 16 hours. Thereafter it was diluted with diethyl ether, washed with water, dried, filtered, concentrated, and then dissolved in hot isopropyl alcohol. Upon cooling solids precipitated from the solution and the product isolated after filtering, mp = 50°C. 

Butyl lithium (10 ml, 1.64 mol in hexane) was added under nitrogen to a stirred suspension of triphenyl-2-pyrrolidinoethylphosphonium bromide (7.2 g) in dry toluene (75 ml). After 0.5 h, ((E)-3-(6-(4-toluoyl)-2-pyridyl)acrylate, vide supra, (4.8 g) in toluene (50 ml) was added. The suspension, initially orange, became deep purple, then slowly faded to yellow during 2 h heating at 75°C. The cooled solution was diluted with ether (150 ml) and treated with hydrochloric acid (50 ml, 2 mol). The aqueous phase was separated, washed with ether, and basified with potassium carbonate (ice) and extracted with ether. The mixture of isomeric esters obtained by evaporation was dissolved in ethanol (100 ml) containing sodium hydroxide solution (20 ml, 1 mol) and partially evaporated on the steam bath under reduced pressure for 5 min. The residual aqueous solution was neutralized with sulfuric acid (20 ml, 0.5 mol) and evaporated to dryness. The solid residue was extracted with hot isopropanol (3x50 ml) and the extracts were concentrated until crystallization commenced. The (E)-3-(6-(3-pyrrolidino-l-(4-tolyl)prop-l-(E)-enyl)-2-pyridyl)acrylic acid, melting point 222°C (dec. recrystallization from isopropanol) was obtained. 

Under an atmosphere of nitrogen, a solution of n-butyl lithium in hexane (321 ml, 15%) was added to a solution of diisopropylamine (48.6 g, 0.48 mole) in tetrahydrofuran (1000 ml) at -30°C and the mixture was stirred for one hour. The reaction mixture was then cooled to -72°C and methyl 3,3-dimethyl acrylate (55 g, 0.48 mole) was added to it. Stirring was continued at -65° to -75°C for 30 min. To the resulting mixture, a solution of p-ionylidene acetaldehyde (100 g, 0.458 mole, 9-trans content 80%) was added and the reaction mixture was stirred at -65° to -75°C for 1 h. The reaction mixture was then warmed to 40°C and stirred at this temperature for 3 h. Solvent was removed under vacuum and the reaction mixture was diluted with water (700 ml) and methanol (300 ml). Activated charcoal (4 g) was then added and the mixture was refluxed for 30 min. The heterogeneous mixture was filtered through hyflo and the hyflo bed was washed with methanol (300 ml) and water (150 ml). The aqueous methanolic layer was then extracted with hexanes (2 x 500 ml) and acidified with 10% sulfuric acid to pH 2.80.5. The desired product was then extracted with dichloromethane (2 x 500 ml). The combined dichloromethane layer was washed with water (2 x 300 ml) and concentrated in vacuo to afford the desired isotretinoin. Crystallization from methanol (200 ml) afforded isotretinoin (44 g) in greater than 99% HPLC purity. 

Budyina and Marinin [130] have described methods based on anodic voltammetry for the determination of lonol (2,6-di- -butyl-p-cresol) and quinol in polyester acrylates. To determine lonol the sample is dissolved in 25 ml of acetone and a portion (10 ml) is treated with 2.5 ml of acetone and 5 ml of methanol and diluted to 25 ml with a solution 0.1 M in lithium chloride and 0.02 M in sodium tetraborate. A polarogram is recorded with a graphite-rod indicator electrode. To determine quinol, the sample (1 to 3 g) is dissolved in 80 ml of methanol or methanohacetone (1 1) and the solution is diluted to 100 ml with the lithium chloride - sodium tetraborate solution. A polarogram is recorded under the same conditions. Concentrations are determined by the addition method. The values versus the SCE) are 0.25 V for lonol and 0.16 V for quinol. 

A solution of terf-butyl-A/ -allyl-[(15)-l-methyl-2-oxoethyl]-carbamate 140 (1.0 g, 4.7 mmol) was treated with ethyl acrylate (1.02 mL, 9.39 mmol) and DABCO (0.63 g, 5.63 mmol) in sulfolane at room temperature for 50 h. Then, the reaction mixture was diluted with water (2 x 20 mL) and extracted with ether (2 x 30 mL). The combined organic layers were washed with brine (25 mL), dried (Na2S04), and concentrated under reduced pressure to get a residue. The residue was purified by column chromatography (silica gel 60-120 mesh, -hexane/EtOAc, 94 6) to afford 0.86 g (58.5%) of acrylate... 

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