Polypropylene flask

Precipitate ferrihydrite by adding 180 mL 5 M KOH to 100 mL M Fe(N03)3 solution. Dilute the suspension to 2 L vith bidistilled vater and hold in a closed polypropylene flask in a 70 °C oven for 60 h. During this time the voluminous redbrown ferrihydrite suspension transforms into a compact yellow precipitate of goethite. Wash well and dry at 50 °C. Around 9 g goethite should be obtained. 

Anhyd HF (10 mL) was condensed at — 10 C into a polypropylene flask containing the oxime (5 g) and EtjO (or EtOH) (50 mL). Then, Clj was bubbled into the mixture. The reaction began a few minutes later. Chlorination was stopped when the characteristic deep-blue color of the nitroso derivatives had vanished and the mixture became brown. After stirring for 4 h, the color was red. The mixture was hydrolyzed with ice (100 g) and extracted with pentane. The organic layer was washed with 10% aq NajCOj and brine, then dried (MgSO ). After removal of the solvent, the products were analyzed and separated by GC. 

Preparation of Zeolites. Preparation was done as previously described (17). The temperature was in the range 90°-100°C. Polypropylene flasks were used throughout. The final pH was measured at ambient temperature after the crystallization. Although different from that at reaction temperature, it provides a convenient comparison between experiments. 

Alkaline treatment of the zeolites was performed in an aqueous 0.2 M NaOH solution. To this end, 660 mg of sample were vigorously stirred in 20 ml of NaOH solution in a polypropylene flask for 30 min at 338 K. Subsequently, the reaction was quenched by immersion of the flask in an ice-water mixture, followed by filtration and thorough washing with demineralized water. The solid product was dried overnight at 373 K and subsequently calcined in static air at 823 K for 5 h. The filtrate was kept for analysis by ICP-OES. The suffix -at denotes alkaline-treated samples. 

Mercury is lost from solutions stored in polypropylene flasks by combination with traces of tin in the polymer. The absorbance of a standard aqueous solution of mercury stored in such flasks was measured for two levels of the following factors ... 

The flasks should be fabricated in accordance with BS 5898 (1980) and the opening should be ground to standard (interchangeable) specifications and fitted with an interchangeable glass or plastic (commonly polypropylene) stopper. They should conform to either Class A or Class B specification BS 1792 (1982) examples of permitted tolerances for Class B grade are as follows ... 

Ny lon-6 (108 g) carpet backed with calcium-carbonate-filled latex and polypropylene was charged to a 1000-mL three-neck round-bottom flask (equipped with a condenser) with 6 mL of 85% phosphoric acid. Superheated steam was injected continuously during a 45-min period. The vapor temperature of the reaction medium was 250-300°C. The volume of distillate collected was 1065 mL. The distillate contained 1.9% e-caprolactam (as determined by GC), which corresponded to a crude yield of 37.5%. The distillate was fractionated in a distillation column and the nonaqueous phase removed. The remaining aqueous phase was treated with 2% potassium permanganate at 40-50°C for 2 h. Evaporation of... 

Drain the aqueous acetonitrile (lower) phase into a 500-mL round-bottom flask, and save the separatory funnel for extraction. Extract the hexane-fat mixture by transferring the mixture back to the polypropylene centrifuge bottle and adding 100 mL of acetonitrile-water (4 1, v/v) solution. Balance the duplicate centrifuge bottles, and cap and shake the bottles for 10 min on the shaker. Centrifuge the second extract at 11 000 rpm for 15 min. Decant this second extract into the 250-mL separatory funnel as before. After phase separation, combine the aqueous extracts in the 500-mL round-bottom flask, and discard the top hexane-fat layer. Add 10 drops of Dow Coming Antifoam B emulsion and 3 mL of 10% aqueous Igepal CO-660 (nonionic surfactant) to the flask. 

ArgoGel-MB-CHO resin (366 mg, 0.42mmol/g substitution) was placed into an Ace pressure tube (note 5). Trimethyl orthoformate (TMOF 5 mL) was added to the flask along with the primary amine (10 equiv.). The tube was capped and heated for 2h at 70°C in a rotating oven (note 6), and cooled. The TMOF solution was removed with the use of a filtration cannula, and the entire process was repeated. The resin was washed with TMOF (5 mL, lx) and anhydrous methanol (5 mL, 3 x) Anhydrous methanol (5 mL) was added to the resin, followed by the addition of sodium borohydride (133 mg, 20 equiv.). After vigorous gas evolution had ceased, the tube was capped and agitated for 8 h at room temperature. The resin was then transferred to a polypropylene reaction vessel and washed with methanol (5mL, 3 x), methanol water (1 1, 5mL, 3 x), DMF water (1 1, 5mL, 3 x), DMF (5mL, 3 x), and methylene chloride (5 mL, 3 x). 

A 3000 molecular weight polypropylene ether) triol (Arcol F3020, 90 g) was mixed with maleic anhydride (60 g) and zinc chloride (2.25 g) in a three-necked round-bottomed flask equipped with a magnetic stirrer, a condensor and a thermometer. Under a nitrogen atmosphere, the reaction mixture was heated to 190 °C... 

In a 250-ml three-necked flask, polypropylene glycol (0.02 mol) and 2,4-toluene diisocyanate (0.042 mol) were added and reacted under conditions provided in Table 1. When the reaction was completed, all products were isolated as transparent colorless liquids. 

For some years a wide range of labware (e.g., flasks, vessels, Erlenmeyer flasks, syringes, separation funnels or even complete distillation apparatus) made of fluoropolymers (Table 4) has been commercially available and can be almost universally utilized over a temperature range of — 270 to + 260 C. Polyethylene and polypropylene can both be used for short periods, however, hydrogen fluoride can remove plasticizers from these polymers resulting in brittleness and also adversely affecting fluorinations. 

Figure 2-9 (a) Class A glass volumetric flask. [Courtesy A. H. Thomas Co., Philadelphia, PA.] (fc>) Class B polypropylene plastic volumetric flask for trace analysis. [Courtesy Fisher Scientific, Pittsburgh, PA.] Class A flasks meet tolerances of Table 2-3. Class B tolerances are twice as big as Class A tolerances, (c) Short-form volumetric flask with Teflon-lined screw cap fits in the analytical balance in Figure 2-3a. Teflon protects the cap from chemical attack. 

All manipulations were carried out under N2 and strictly anhydrous conditions. Trt-Xaa -MBHA-PSty-resin (250 mg, 11.07 mmol) in polypropylene packet (5 x 5 cm) was dried overnight at 50 mTorr. The packet was placed in a round-bottomed flask. 1M LiOtBu in THF (22 mL, 22 mmol) and THF (22 mL) were added and the vessels shaken for 15 min. Excess base soln was removed by cannulation, following addition of DMSO (44 mL) and the alkylating agent (66.5 mmol). The mixture was vigorously shaken at... 

Yandenburg et al. [92] compared extraction of additive Irganox 1010 from freeze-ground polypropylene polymer by pressurized fluid extraction (PFE) and MAE with reflux, ultrasonic, shake-flask, and Soxhlet extraction. PFE and MAE were faster than any conventional method with comparable extraction efficiency. The times to reach 90% recovery by PFE using propan-2-ol at 150°C and acetone at 140°C were 5 and 6 minutes, respectively. Reflux with chloroform was found to be the fastest method performed under atmospheric pressure with 90% recovery in 24 minutes. Reflux with cyclohexane propan-2-ol (1 1) required 38 minutes. Ultrasonic, shake-flask, and Soxhlet extraction required about 80 minutes (90%) extraction). The total sample preparation time for PFE was 15 minutes, MAE 28 minutes, and reflux with chloroform was 45 minutes. 

Gramiccioni et al. [187] reported the determination of residual ethylene oxide in sterilized polypropylene syringes and in materials such as plasticized PVC, polyurethane, and para rubber. The sterilized object was cut into small pieces, weighed, and placed into a flask containing N,N-dimethylacetamide (DMA). The flask was capped and shaken to make the sample homogeneous. After 24 hr it was shaken again and a sample was... 

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