Environment-friendly solvent

In an article dealing with applications of olefin CM to a series of commercial products [138], solvent-free CM between ( )-3-hexene (produced by homocoupling of 1-butene) and 11-eicosenyl acetate 303 (produced from jojoba oil) was used to produce acetate 304 (Scheme 59), which is - as a natural 82 18 (EIZ) mixture - the pheromone of omnivorous leafroller, and serves as an environment-friendly pest controlling agent. The CM reaction was performed without solvent at 5 °C with a 4 1 mixture of ( )-3-hexene and 303, in the presence of only 0.2 mol% catalyst C, and furnished after 20 h coupling product 304 ( Z=83 17) in 50% yield. 

When an electron-deficient BT unit was incorporated into the backbone of these polymers, an efficient energy transfer resulted in complete fluorescence quenching from the fluorene sites already at BT concentrations as low as 1% (for both neutral and quaternized copolymers, 377 and 378) [440] (Chart 2.93). These macromolecules emit green (544-550 nm, 377) to yellow (555-580 nm, 378) light and can be processed from environment-friendly solvents such as alcohols. The PLED fabricated with these polymers showed high 4>(]over 3 and 1% for 377 and 378, respectively (A1 cathode). 

Taylor A. McCarty received her BA in biology and chemistry from SUNY Potsdam in 2003. She recently obtained her PhD in analyhcal chemistry from the University at Buffalo under the supervision of Dr. Frank Bright, where she is now the lab manager. Her research interests include the behavior of macromolecules such as polymers and proteins dissolved in environment-friendly solvent systems. 

The polyurethane (PU) can be considered an environment-friendly material because the urethane bond resembles the amide bond, which implies possible biodegradability. It can be used in various elastomer formulations, paints, adhesives for polymers and glass, and artificial leather as well as in biomedical and cosmetic fields. Polyurethane spheres were prepared from 20/40% of PU prepolymer solution in xylene [91]. PU droplets were formed in water with the SPG membrane of different pore size (1.5-9.5 pm) and then polymerized to form the final microspheres. Finally, spherical and solid PU particles of 5 pm were obtained after the removal of the solvent. In another study, Ma et al. reported the formation of uniform polyurethane-vinylpolymer (PUU-VP) hybrid microspheres of about 20 pm, prepared using SPG membranes and a subsequent radical suspension polymerization process [92], The prepolymers were solubilized in xylene and pressed through the SPG membrane into the continuous phase containing a stabilizer to form uniform droplets. The droplets were left for chain extension at room temperature for some hours with di- and triamines by suspension polymerization at 70 °C for 24h. Solid and spherical PU-VP hybrid particles with a smooth surface and a higher destructive strength were obtained. 

A synthesis of quinolines from reaction of 2-isopropenylaniline hydrochloride with cyclic ketones was described. The method employs a hydrothermal process with no organic solvents involved <030L1605>. The authors suggest this as an environment-friendly process. The product yields and side product formations are heavily dependent upon reaction temperature. 

Carbon dioxide is, by far, the most attractive SCF for many reasons It is inexpensive and abundant at high purity (food grade) worldwide and it is nonflammable, non-toxic, and environment friendly moreover, its critical temperature T = 31 °C) permits operations at near-ambient temperature which avoids product alteration and its critical pressure (= 74 bar) leads to acceptable operation pressure, generally between 100 and 350 bar. In fact, supercritical carbon dioxide behaves as a rather weak nonpolar solvent, but its solvent power and polarity can be significantly increased by adding a polar cosolvent that is chosen among alcohols, esters, and ketones. Ethanol is often preferred because it is not hazardous to the environment, not very toxic, and available pure at low cost. Hydro fluorocarbons (HFCs) are very costly and their specific properties rarely justify their use in the replacement of carbon dioxide. 

The fast-growing process of urbanization, industrialization, and unethical agriculture that has been implemented until recently has neither taken in consideration nor foreseen its effect on the environment, flora and fauna, and peoples health and safety. Thus, over the last decade, green chemistry research has been focusing on finding and using safer and more environment-friendly solvents. 

These demonstrations of melt processability for PAn provide an avenue for the convenient preparation of films and fibers of CEPs. The absence of solvent makes the melt-processing route more attractive and environment-friendly than alternative solvent processing. In addition, the melt-processable CEPs are then easily incorporated into polymer blends using the well-developed processing techniques (extrusion and so on) widely used for thermoplastic polymers. 

Huang, F. Wu, H. B. Peng, J. B. Yang, W. and Cao, Y. 2007. Polyfluorene polyelectrolytes and their precursors processable from environment-friendly solvents (alcohol or water) for PLED applications. Curr. Org. Chem. 11 1207-1219. 

The last examples clearly demonstrate that photosensitive low molecular film-forming ISA complexes are viable alternatives to photosensitive polymers. The ISA complexes have several advantages in comparison to functionalized polymers (i) low production cost due to cheap starting materials (ii) ability to induce higher values of anisotropy (iii) thermal stability of induced anisotropy and (iv) solubility of ISA complexes in environment-friendly solvents such as ethanol. 

Cellulosic fibers are characterized by favorable properties such as renewability, biodegradability, environment friendly, excellent affinity for chemical functionalization as well as potential applicability [149]. Cellulosic fibers may be natural, such as cotton, flax, and jute, or regenerated fibers such as lyocell, using NMMO [N-methyl, morpholine-N-oxide] as a solvent for cellulose pulp, viscose, via, more environment-friendly viscose process, as well as bamhoo viscose fibers [24,142,149]. 

Indeed, the tuneable properties of ILs associated with their environment-friendly perception have increased their investigation as alternative reaction media to replace traditional organic solvents in organic synthesis [11-13], catalytic reactions [12-16], electrochemical applications [17-19], biochemistry [20-24], and material engineering [25], It has also been reported that ILs can be used in extraction and as liquid phase in supported liquid membranes (SLMs) for the separation and recovery of organic compounds, metals, and gases [26-31]. 

A perfect solvent to displace water should have the high density and low interfacial tension for water. It should also be nontoxic, inflanunable, immiscible with water, and chemically inert. As a displacement liquid, a variety of organic solvents can be used. Of these, freon F-113 is the most frequently selected because it is nontoxic (T.V.A.—1000 ppm), its density is 50% greater than the density of water, its boiling point is only 48°C, and the latent heat of evaporation at the boiling point is 146.5 kJ/kg. Unfortunately, freons are not environment-friendly, so their use is restricted in various countries. In either case, the system should be perfectly tight to avoid gas release. 

In recent years, some monoterpenes have attracted some interest as environment-friendly solvents for polymeric systems. Camphene, which is both harmless and readily sublimed, has been tested as solvent for polypropylene... 

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