Polypropylene filters

Syringe filter, polypropylene, 25 mm diameter, 0.45micrometer pore size with binder-free glass fiber prefilter Syringe filter, PTFE, 25 mm diameter, 1.0 micrometer pore size Syringe filter) PTFEt 25 mm diameter, 0.45 micrometer pore size Syringe filter LC. 25 mm diameter, 0.45 micrometer pore size Sterilization filter unit, nylon, 200ml, 0.45 micrometer pore size Sterilization Filter Unit cellulose acetate, 0.45 micrometer Sterilization Filter Unit cellulose nitrate 0.45 micrometer... 

The resin is anchored to the linker using standard chemistry for amide bond formation. Originally only two equivalents of o-PALdehyde were used however, the coupling of the linker obviously proceeds faster with higher concentrations and larger equivalents. The protocol below was developed for use with glass vials with a filter polypropylene for microwave synthesis. 

A common surface cartridge is the pleated paper constmction type, which allows larger filtration areas to be packed iato a small space. Oil filters ia the automobile iadustry are of this type. The paper is impregnated, for strength, with epoxy or polyurethane resia. Any other medium ia sheet form, similar to cellulose paper, such as wool, polypropylene, or glass may be used. 

Chemically Resistant Fibers. Fibers with exceUent chemical resistance to corrosive and/or chemical warfare agents or extreme pH conditions (eg, very acidic or very alkaline) were initially used for protective clothing. However, appHcations for filtration of gases and Hquids in numerous industrial faciHties are now the more important. For example, PPS is suitable for use in filter fabrics for coal-fired boilers because of its outstanding chemical and heat resistance to acidic flue gases and its exceUent durabUity under these end use conditions. Many high tenacity fibers are also chemically inert or relatively unaffected under a variety of conditions. Aramids, gel spun polyethylene, polypropylene, fluorocarbon, and carbon fibers meet these criteria and have been used or are being considered for appHcations where chemical resistance is important. 

Hydrofluoric acid [7664-39-3] M 20.0, b 112.2"(aq azeotrope, 38.2% HF), d 1.15 (47-53% HF), pK 3.21. Freed from lead (Pb ca 0.002ppm) by co-precipitation with Srp2, by addition of lOmL of 10% SrCl2 soln per kilogram of the cone acid. After the ppte has settled, the supernatant is decanted through a filter in a hard-rubber or paraffin lined-glass vessel [Rosenqvist Am J Sci 240 358 1942. Pure aqueous HF solutions (up to 25M) can be prepared by isothermal distn in polyethylene, polypropylene or platinum apparatus [Kwestroo and Visser Analyst 90 297 7965]. HIGHLY TOXIC. 

Operating conditions are important determinants of the choice of filter media and sealant used in the cartridges. Some filter media, such as cellulose paper filters, are useful only at relatively low temperatures of 95 to 150"C (200 to 300°F). For high-temperature flue gas streams, more thermally stable filter media, such as nonwoven polyester, polypropylene, or Nomex, must be used. A variety of commercially available sealants such as polyurethane plastic and epoxy will allow fabric operating temperatures up tol50°C (300°F). Selected sealants such as heat cured Plasitcol will withstand operating temperatures up to 200°C (400°F). 

From the viewpoint of accommodation to the filter-supporting structure, some cloths cannot be used, even though the filtering characteristics are excellent. For rotary drum filters, for example, the cloth is pressed onto the drum by the caulking method, which uses cords that pass over the drum. In this case, the closely woven cloths manufactured from monofilament polyethylene or polypropylene fiber are less desirable than more flexible cloths of polyfilament fibers or staple cloths. 

Utilize the filter tool to insert the polypropylene filter plate on top of the gel. Get rid of any gel particles above the filter by thoroughly rinsing with water. 

In many countries starter batteries are almost 100 percent recycled PVC separators can cause some problems here [67]. A prior separation of PVC from other battery components, which is quite tedious, would be desirable, because a PVC content decreases the recycling purity of the container polypropylene and makes further processing of this plastic more difficult. Also, any chlorine compounds liberated can form environmentally hazardous products with other substances the usual remedy is to install costly filter stations, with the residues representing possibly toxic wastes requiring special disposal methods. 

Microwave-assisted solid-phase parallel synthesis has also been reported using multi-well filter-bottom polypropylene plates [45,155]. However, it should be mentioned that the thermal instability of the polypropylene plates is a limitation of this setup. In addition, uneven heating across the plate results in higher temperatures (AT 10-20 °C) being observed at the center of the plate than at the edges. 

Recently, Murray and Gellman demonstrated that parallel synthesis in inexpensive 96-well polypropylene filter plates with microwave irradiation in a multimode reactor is a simple and effective method for the rapid preparation of j8-peptide hbraries on sohd support in acceptable purities [156]. 

A polypropylene filter, which contained zinc oxide, reacted explosively in contact with chlorine and was destroyed. This filter was tested at 300 bar. Zinc chloride, which is formed by the effect of chlorine on zinc oxide, may have catalysed this reaction. 

Waters Seawater (National Research Council Canada 1992) was collected in the North Atlantic Ocean at a depth of 10 m, 35 km southeast of Hahfax, Nova Scotia, Canada. The water was peristaltically pumped through cleaned polyethylene-hned ethyl vinyl acetate tubing and 0.45-pm acrylic copolymer filters. It was acidified to pH 1.6 with ultrapure nitric acid during its immediate transfer to 50-L acid-leached polypropylene carboys, previously conditioned with ultrapure water acidified to pH 1.6. The seawater was later homogenized in two linked 800-L polyethylene tanks in a clean room and immediately bottled in cleaned 2-L polyethylene bottles. Randomly selected bottles were used for analytical measurements. 

Ultrasonication was reported for the extraction of triazines from soil, previously sieved to 2 mm and stored at -18 °C, prior to analysis using CC/NPD and CC/lTD. A 5-g soil sample was placed in a polypropylene column and extracted for 15 min with 4 mL of ethyl acetate in an ultrasonic bath at room temperature. Subsequently, the solvent was filtered and collected in a graduated tube, and the extraction was repeated for another 15-min period using a second 4-mL portion of ethyl acetate. The two extracts... 

Concentrated metal hydroxide sludge is pumped from the clarifier to a polypropylene plate filter press [T-102], The plate filter press56 is of sufficient capacity without any buildup in the lamellar portion of the unit. This also prevents any overflow of precipitate to the sewer system. The metal hydroxides form a dense sludge cake suitable for disposal in an approved landfill. The liquid effluent from the plate filter is returned to the surge tank [T-99],... 

During solution polymerization the monomer, catalyst, and diluent are introduced to a reactor maintained at a temperature between 175 and 250 °C. The resulting polymer forms a viscous solution in the solvent, which is pumped out of the reactor. If necessary, the solution can be filtered to remove the catalyst residue. Solvent is removed from the solution and recycled, leaving behind a mixture of isotactic and a small amount of atactic polypropylene. 

In a review of incidents involving explosive reactivity of liquid chlorine with various organic auxiliary materials, two involved hydrocarbons. A polypropylene filter element fabricated with zinc oxide filler reacted explosively, rupturing the steel case previously tested to over 300 bar. Zinc chloride derived from the oxide may have initiated the runaway reaction. Hydrocarbon-based diaphragm pump oils or metal-drawing waxes were violently or explosively reactive [8], A violent explosion in a wax chlorination plant may have involved unplanned contact of liquid chlorine with wax or chlorinated wax residues in a steel trap. Corrosion products in the trap may have catalysed the runaway reaction, but hydrogen (also liberated by corrosion in the trap) may also have been involved [9],... 

Several articles in the area of microwave-assisted parallel synthesis have described irradiation of 96-well filter-bottom polypropylene plates in conventional household microwave ovens for high-throughput synthesis. While some authors have not reported any difficulties in relation to the use of such equipment (see Scheme 4.24) [77], others have experienced problems in connection with the thermal instability of the polypropylene material itself [89], and with respect to the creation of temperature gradients between individual wells upon microwave heating [89, 90]. Figure 4.5 shows the temperature gradients after irradiation of a conventional 96-well plate for 1 min in a domestic microwave oven. For the particular chemistry involved (Scheme 7.45), the 20 °C difference between the inner and outer wells was, however, not critical. 

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