Filter polystyrene

Assemble the polystyrene cassette filter holder, using the appropriate filter for the sampling method. Compress cassette by using a mechanical press or other means of applying pressure. Use shrink tape around cassette... 

The retentivity relative to solid particles (e.g., spherical particles of polystyrene of definite size) is found from experiments determining the amount of these particles in the suspension to be filtered before and after the filter media. The retentivity K is determined as follows where g, g" =amounts of solid particles in liquid sample before and after the medium, respectively. 

Under argon, to a mixture of 2,5-dichlorobenzophenone (2.5 g, 10 mmol), zinc (2.0 g, 30.6 mmol), NiCl2 (0.13 g, 1 mmol), PPh3 (1.04 g, 4 mmol), and bipyridine (01.6 g, 1.01 mmol) was added 30 mL DMF. The mixture was heated to 70°C and stirred at that temperature for 20 h. The reaction mixture was then dispersed into acetone. The solid was filtered and washed with 5% HC1 (3 times), water (3 times), and acetone. Polymer 57 was obtained in quantitative yield as a yellowish powder. GPC (polystyrene standards) Mw = 58,000. 

Under nitrogen, anhydrous DMF (10 mL) was added to a mixture of 83 (0.240 g, 0.5 mmol), 84 (0.063 g, 0.5 mmol), and Et3N (1 mL). Pd(PPh3)4 (0.027 g, 0.025 mmol) and Cul (0.005 g, 0.025 mmol) were then added and the reaction mixture was stirred at 100°C for 48 h. After being cooled to room temperature, die reaction mixture was poured into MeOH and filtered. The solid was washed with MeOH and dried under vacuum. The repetition of the precipitation procedure gave polymer 85 as orange powder in 96% yield (0.212 g). GPC (polystyrene standards) Mn — 15.100. 

To a mixture of 1,3-dibromobenzene (4.36 g, 18.49 mmol), 1,3-phenylene diamine 111 (2.00 g, 18.49 mmol), NaO-t-Bu (3.73 g, 38.84 mmol), Pd2(dba)3 (0.339 g, 0.37 mmol), and BINAP (0.691 g, 1.11 mmol) in a heavy-walled flask equipped with a Teflon valve was added THF (15 mL) under inert atmosphere. The flask was sealed and heated to 90°C. After 24 h, die reaction mixture was cooled to room temperature and neutralized using 0.2 mol equivalents of 2.4 N HC1 in MeOH. The polymer was precipitated from hexanes, filtered, and dried under vacuum. The dried polymer was redissolved in THF, filtered through Celite, and reprecipitated. The solid was collected by filtration and dien purified by Soxlilet extraction with CH2C12 overnight. After drying under vacuum, a green-tan solid was obtain in 106% yield. GPC (NMP, polystyrene standards) Mw = 39,000 ... 

Under argon, a mixture of 145 (0.046 mmol), 132 (0.046 mmol), Pd(PPli3)4 (0.2 (junol), Cul (0.2 [miol), and diisopropylamine (0.015 mmol) in THF (4 mL) was stirred in the dark at 50°C for 2 days. Ethynylbenzene (0.92 mmol) was then added and stirred at 50°C overnight. After concentration, die residue was dissolved in CHCI3 and filtered. The filtrate was subjected to preparative SEC with CHCI3 as eluent in order to remove catalyst residues and unreacted starting materials. Polymer 42 was obtained as a yellow solid in 85% yield. SEC analysis (THF, polystyrene standards) Mw = 280,000 (PDI = 6.5). 

Barium and strontium salts of polystyrene with two active end-groups per chain were prepared by Francois et al.82). Direct electron transfer from tiny metal particles deposited on a filter through which a THF solution of the monomer was percolated yields the required polymers 82). The A.max of the resulting solution depends on the DPn of the formed oligomers, being identical with that of the salt of polymers with one active end-group per chain for DPn > 10, but is red-shifted at lower DPn. Moreover, for low DPn, (<5), the absorption peak splits due to chromophor-chromophor interaction caused by the vicinity of the reactive benzyl type anions. 

A well-known high conversion reactor is the so-called polymerization press, a modified plate-and-frame filter press where polystyrene is polymerized in frames alternating between cooling platens through which water (or steam) can be circulated. Other versions of the high conversion reactor have been utilized, e.g., the early "can process of Dow, where styrene monomer was placed in sealed cans in water baths and the metal stripped off at the end of the polymerization 2). 

A primary and secondary treatment plant to handle all process water. Any solid waste that cannot be sold will be used for landfill. All air laden with polystyrene dust will be sent through bag filters before it is discharged to the atmosphere. 

In the early 1970 s, Bayer et al. reported the first use of soluble polymers as supports for the homogeneous catalysts. [52] They used non-crosslinked linear polystyrene (Mw ca. 100 000), which was chloromethylated and converted by treatment with potassium diphenylphosphide into soluble polydiphenyl(styrylmethyl)phosphines. Soluble macromolecular metal complexes were prepared by addition of various metal precursors e.g. [Rh(PPh3)Cl] and [RhH(CO)(PPh3)3]. The first complex was used in the hydrogenation reaction of 1-pentene at 22°C and 1 atm. H2. After 24 h (50% conversion in 3 h) the reaction solution was filtered through a polyamide membrane [53] and the catalysts could be retained quantitatively in the membrane filtration cell. [54] The catalyst was recycled 5 times. Using the second complex, a hydroformylation reaction of 1-pentene was carried out. After 72 h the reaction mixture was filtered through a polyamide membrane and recycled twice. 

Figure 12.5 [18] Structure of the monolayer of S05-3 arborescent graft (dendri-graft) polystyrenes cast on mica as prepared (A) and Fourier filtered (B)...

These polystyrene-based catalysts are effective for the cyanide displacements of 1-bromooctane and 1-chlorooctane, and also for the generation of dichlorocarbene from chloroform and aqueous sodium hydroxide, giving quantitative yields of (2,2-dichlorocyclopropyl)benzene from styrene. The catalysts may be recovered simply by filtering the reaction mixture. Unfunctionalized polystyrene does not catalyse these reactions. As well as improving product purification and catalyst recovery, this approach also avoids... 

Filters. The filter unit consists of a three-piece polystyrene cassette, a backup pad and a filter (Figure 4) 2). 

Sample Preparation. Calibration standards and test solutes were injected ai dilute solutions in the eluent. Polystyrene standards were 0.03 (w/v). Styrene, ODCB and normal hydrocarbons were 0.15 (w/v), except for dodecane and tridecane (0.65 ). Samples involving more complex matrices were prepared by crushing (if necessary), dissolving a weighed amount in the eluent, and filtering through a 0.45 Millex-SR filter cartridge (Millipore, Bedford, ma). 

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