Polyurethane, extraction

We attempted to develop a multipurpose extraction system by combining the carbon adsorption and polyurethane extraction techniques. Our research continues. Our first experiments focused on the production of a carbon-impregnated reticulated foam. Several companies promote this technology, but in our tests, the method of incorporation of the carbon significantly reduced the activity of the carbon. 

ESCA Studies of Extracted Polyurethanes and Polyurethane Extracts Biomedical Implications... 

Benzene, toluene, and xylene are made mosdy from catalytic reforming of naphthas with units similar to those already discussed. As a gross mixture, these aromatics are the backbone of gasoline blending for high octane numbers. However, there are many chemicals derived from these same aromatics thus many aromatic petrochemicals have their beginning by selective extraction from naphtha or gas—oil reformate. Benzene and cyclohexane are responsible for products such as nylon and polyester fibers, polystyrene, epoxy resins (qv), phenolic resins (qv), and polyurethanes (see Fibers Styrene plastics Urethane POLYiffiRs). 

A hst of polyol producers is shown in Table 6. Each producer has a varied line of PPO and EOPO copolymers for polyurethane use. Polyols are usually produced in a semibatch mode in stainless steel autoclaves using basic catalysis. Autoclaves in use range from one gallon (3.785 L) size in research faciUties to 20,000 gallon (75.7 m ) commercial vessels. In semibatch operation, starter and catalyst are charged to the reactor and the water formed is removed under vacuum. Sometimes an intermediate is made and stored because a 30—100 dilution of starter with PO would require an extraordinary reactor to provide adequate stirring. PO and/or EO are added continuously until the desired OH No. is reached the reaction is stopped and the catalyst is removed. A uniform addition rate and temperature profile is required to keep unsaturation the same from batch to batch. The KOH catalyst can be removed by absorbent treatment (140), extraction into water (141), neutralization and/or crystallization of the salt (142—147), and ion exchange (148—150). 

We achieved, that by contact of polyurethane foam with water solution of molybdophosphate, contain by pH 1-2,5 mixture of saturated (5 NMR P=-3.20 p.p.m. apply to 85 % H PO ) and unsaturated monovacant (x=0-t-4) (5 NMR P = -0,96 p.p.m.) heteropolycomplexes Keggin staicture, equilibrium discharge in the direction produced of saturated heteropolycomplex of Dowson stmcture and on the surface of polyurethan foam formed 18-molybdo-2-phosphate acid ( P = -2,40 p.p.m. in ether extract). The formed surfaces heteropolycomplex is stable for action 1 M solution of strong acids and basics and have ion exchanged properties in static and dynamic conditions to relation to macro and micro amount of M(I) ... 

Meluch et al.10 reported that high-pressure steam hydrolyzes flexible polyurethane foams rapidly at temperatures of 232-316°C. The diamines are distilled and extracted from the steam and the polyols are isolated from the hydrolysis residue. Good results were obtained by using reclaimed polyol in flexible-foam recipes at file 5% level. Mahoney et al.53 reported the reaction of polyurethane foams with superheated water at 200°C for 15 min to form toluene diamines and polypropylene oxide. Gerlock et al.54 studied the mechanism and kinetics of the reaction... 

An immersion time less than 1 min, the neutralization with ammonium hydroxide (it extracts the hydrogen from the sulfonic acid and leaves stabilized S03 NH4 ion pair), and the high concentration of the sulfuric acid (95 wt%) are essential to produce adequate effectiveness of the treatment. H2SO4 treatment increases the T-peel strength of treated TR or SBR-polyurethane adhesive joints (Figure 27.2). 

Application verification (AV) monitors are devices that are placed within test plots to measure actual spray deposition that occurred during application. The main function of AV monitors is to show whether or not the intended amount of test material was actually deposited on the soil surface. Application monitors consisting of soil-filled containers, paper disks, polyurethane foam plugs, and glass Petri dishes have all been used successfully for this purpose. Prior to using a monitor in the field, it is important to determine that the test substance can indeed be successfully extracted from the monitor and that the compound will be stable on the monitor under field conditions... 

Various additives in PE (Santonox, Nonox DPPD, Neozone A, Ionol and Agerite White) were determined by conventional TLC [507]. Other additives in PE, studied by means of TLC, were Tinuvin P 120/326/327/770, Cyasorb UV531, Anti UV P (2-hydroxy-4-n-octyloxybenzophenone), Irganox 1076, Sanduvor EPU, AO-4 and Dastib 242/263 [508], TLC has also been used in the analysis of additives in polyurethanes [509,510] as well as of slip additives (ethoxylated amines and amides) in HDPE extracts... 

Applications Off-line SFE-GC-MS has been used for the analysis of additives in polyurethanes [52], Marin et al. [53] have used off-line SFE-GC to determine the detection limits for DOP and DBP in flexible PVC. The method was compared with Soxhlet liquid extraction. 

Flame retardants in polyurethane foams were determined by SFE-SFC [117]. Off-line SFE-SFC-FID was used for the analysis of additives in polyurethanes [52], and on-line SFE-SFC for extraction of additives from isocyanate formulations [107]. 

Applications A TLC-fluorimetric method has been described for the determination of 2,4- and 2,6-diaminotoluene in methanol extracts of flexible polyurethane foams [736]. The precision of this method at the... 

The PUF roller technique consists of placing a cylinder of polyurethane foam (PUF) onto a weighted, stainless steel roller and then rolling it over a defined area of treated turf. The turf is typically rolled over three times. The PUF is then pulled off the weighted, stainless steel roller, extracted, and analyzed for residues. 

Ligocki MP, Pankow JF. 1985. Assessment of adsorption/solvent extraction with polyurethane foam and adsorption/thermal desorption with Tenax-GC for the collection and analysis of ambient organic vapors. Anal Chem 57 1138-1144. 

A gaseous sample is passed through a solid material, such as silica gel or polyurethane foam (PUF), in a tube. A glass fiber filter is often put in front of the solid support to capture particle-phase constituents, while the vapor-phase compounds are captured on the solid support. This is used for semivolatile analytes, such as polycyclic aromatic hydrocarbons and pesticides. The solid support is then usually extracted in the lab with a solvent (see techniques described later in this chapter), and then the techniques used for liquid samples are followed. 

Aira Adsorption/solvent extraction with polyurethane foam plug HRGC/MS No data No data Ligocki and Pankow 1985... 

Ai r Collection on particulate filter and polyurethane foam Soxhlet extraction alumina column clean-up GC/ECD 0.1 ng/m3 >95... 

Lake sediments Ultrasonic solvent extraction clean-up on Florisil column separation of mi rex and photomi rex from PCBs using charcoal -polyurethane column GC/ECD No data <0.05 ppm 99.9-100 (mi rex) 95.1-99.1 (photomi rex) Chau and Babjak 1979... 

H2SO4 = sulfuric acid IDL = insturmental detection limit MS = mass spectrometry MSD = mas selective detctor Na2S04 = sodium sulfate PCBs = poylchiorinated biphenlys PUR = polyurethane foam SIM = selective ion monitoring SPE = solid phase extraction... 

Sample collected with low-volume sampler consisting of a constant flow pump and a cartridge containing polyurethane foam. Extract with diethyl ether in hexane. 

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