Propylene oxide Volume

Poly(propylene oxide) [25322-69-4] may be abbreviated PPO and copolymers of PO and ethylene oxide (EO) are referred to as EOPO. Diol poly(propylene oxide) is commonly referred to by the common name poly(propylene glycol) (PPG). Propylene oxide [75-56-9] and poly(propylene oxide) and its copolymers, with ethylene oxide, have by far the largest volume and importance in the polyurethane (PUR) and surfactant industry compared to all other polyepoxides. Articles reviewing propylene oxide (1), poly(propylene oxide) (2—4), other poly(aIkylene oxides) (4), and polyurethanes (5—7) are cited to lead the interested reader to additional detail not in the scope of this article. 

Styrene manufacture by dehydrogenation of ethylbenzene is simple ia concept and has the virtue of beiag a siagle-product technology, an important consideration for a product of such enormous volume. This route is used for nearly 90% of the worldwide styrene production. The rest is obtained from the coproduction of propylene oxide (PO) and styrene (SM). The PO—SM route is complex and capital-iatensive ia comparison to dehydrogenation of ethylbenzene, but it stiU can be very attractive. However, its use is limited by the mismatch between the demands for styrene and propylene oxides (qv). 

Uses of Ghlorohydrins From a volume standpoint almost all of the chlorohydrins produced are immediately converted into epoxides such as propylene oxide and epicblorobydrin. The small quantity of various chlorohydrins sold in the merchant market are used in specialty appHcations. 

The 1997 U.S. propylene demand ws 31 billion pounds and most of it was used to produce polypropylene polymers and copolymers (about 46%). Other large volume uses are acrylonitrile for synthetic fibers (Ca 13%), propylene oxide (Ca 10%), cumene (Ca 8%) and oxo alcohols (Ca 7%). ... 

Uses Used in the petroleum industry to make so-called alkylate for improved octane gasoline. Large quantities are polymerized to polypropylene for carpeting, upholstery, ropes, and other uses. Used in the chemical industry as a starting material for many large-volume chemicals such as acetone, acrylonitrile, and propylene oxide. 

Morey et al. (25) synthesized Ti-SBA-15 with uniform tubular channels (surface area = 600-900 m2/g, pore volume = 0.6-1.3 cm3/g, average pore diameter = 6.9 nm) by direct and postsynthesis methods by using triblock copolymers, poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) in... 

This is a very important group of products and most of them are adducts of long-chain alcohols or alkylphenols with a number of ethylene oxide (EO) units. Adducts with propylene oxide (PO) and copolymers of ethylene and PO are also used although they are less important in terms of usage volume than the pure ethoxylate derivatives. 

The epoxidation of propylene to propylene oxide is a high-volume process, using about 10% of the propylene produced in the world via one of two processes [127]. The oldest technology is called the chlorohydrin process and uses propylene, chlorine and water as its feedstocks. Due to the environmental costs of chlorine and the development of the more-efficient direct epoxidation over Ti02/Si02 catalysts, new plants all use the hydroperoxide route. The disadvantage here is the co-production of stoichiometric amounts of styrene or butyl alcohol, which means that the process economics are dependent on finding markets not only for the product of interest, but also for the co-product The hydroperoxide route has been practiced commercially since 1979 to co-produce propylene oxide and styrene [128], so when TS-1 was developed, epoxidation was looked at extensively [129]. 

The density of the polymer clearly shows the formation of a foamed polymer. The density values for selected foams together with the polyimide homopolymers are shown in Table 11. The density values for the ODPA/FDA and PM-DA/FDA polyimides were both 1.28 g/cm and 3FDA/PMDA is 1.34, while most of the propylene oxide-based copolymers showed substantially lower values. The densities of the foamed copolymers derived from these copolymers ranged from 1.09 to 1.27 g/cm, which is 85-99 % of that of the polyimide homopolymers. This is consistent with 1-15 % of the film being occupied by voids. From these data (i.e., the comparison of Tables 10 and 11), it appears that the volume fraction of voids or the porosity is substantially less than the volume fraction of propylene oxide in the copolymer (i.e., 70 % or less). Thus the efficiency of foam formation is poor. Conversely, the propylene oxide-based copolymers with PMDA/ODA as the imide component did not show the expected density drop, and the values were essentially identical to that of the homopolymer. In PM-DA/ODA-based systems, molecular ordering and orientation were found to be critical in determining the stability of the foam structure. Where the character-... 

Foam formation was possible only in the amorphous high Tg polyimides however, the volume fraction of voids does not correspond to the volume fraction of propylene oxide in the initial copolymer. A decrease in the volume fraction of voids incorporated into the matrix in comparison to the initial volume fraction of the propylene oxide in the copolymer can be understood by consid-... 

Atmospheres containing hydrogen, fuel and combustible process gases containing more than 30% hydrogen by volume, or gases or vapors of equivalent hazard such as butadiene, ethylene oxide, propylene oxide and acrolein. Group B ... 

Vanta et al (Ref 2) determined the detonation limits of propylene oxide/air mixts to be 2.7 to 14.4 volume %, or much narrower than the flammability limits of ethylene oxide/air (see Table 3). They also measured the lower detonation limit for n-propyl nitrate/air and found it to be 2.2 volume %... 

The [l-(benzhydrylamino)alkyl]phosphinic acid 32 was heated with an excess of 48% HBr (5 times weight) at 100 °C for 1-2 h until two distinct phases separated. (Note the 48% HBr is pretreated by extraction three times with an equal volume of CH2C12 to remove any bromine, which oxidizes the phosphinic acid.) The mixture was concentrated to dryness under reduced pressure and the residue was taken up in H20. The aqueous soln was washed several times with Et20 to remove DpmBr and concentrated to a thick oil. (Note complete removal of the solvent is important at this point otherwise, residual HBr interferes in the next step.) The oily residue of 1-aminoalkylphosphinic acid hydrobromide was dissolved in EtOH (lOmL-g ) and propylene oxide was added dropwise until precipitation began. The mixture was allowed to stand until precipitation was complete, and the solid 33 was collected by filtration, washed successively with EtOH and Et20, and dried. For Alap analogue mp 223-224 °C 31P NMR (D20, 5) 22.2. 

A mixture of the alkylated adducts 39 and 1.5M HC1 (15-20mL-mmol ) was heated to reflux for 2-8h until hydrolysis was complete, as determined by 31P NMR. The mixture was concentrated in vacuo, the residue was dissolved in H20, and the soln was washed with Et20 and reconcentrated in vacuo. The product was finally purified by ion-exchange chromatography or by dissolution in hot EtOH (twice the minimum volume required) followed by cooling to rt and precipitation of the zwitterion by the addition of propylene oxide. The 1-aminoalkylphosphinic acids 33 were isolated as white solids. 

The first generation of research involving surfactants in SCFs addressed water/oil (w/o) microemulsions (Fulton and Smith, 1988 Johnston et al., 1989) and polymer latexes (Everett and Stageman, 1978) in ethane and propane (Bartscherer et al., 1995 Fulton, 1999 McFann and Johnston, 1999). This work provided a foundation for studies in C02, which has modestly weaker van der Waals forces (polarizability per volume) than ethane. Consequently, polymers with low cohesive energy densities and thus low surface tensions are the most soluble in C02 for example, fluor-oacrylates (DeSimone et al., 1992), fluorocarbons, fluoroethers (Singley et al., 1997), siloxanes, and to a lesser extent propylene oxide. Since C02 is... 

In the formation of propylene oxide via the stage of allyl alcohol release to the free volume and interaction with the catalyst, isomerization is of low probability because of unfavorable change in the free energy ... 

The coordination polymerisation and copolymerisation of heterocyclic monomers have been restricted in industry to a much smaller volume than the polymerisation and copolymerisation of hydrocarbon monomers polyether elastomers from epichlorohydrin and ethylene oxide or propylene oxide, and allyl glycidyl ether as the vulcanisable monomeric unit, are produced on a larger scale [4-7],... 

The largest-volume polyether used is obtained from propylene oxide polymerized under basic conditions. Polyester polyols are produced from a number of different materials involving diacids and diols to give the ester linkage. Aliphatic polyesters generally are used for elastomers to impart chain flexibility. 

Figure 1. Specific volume change vs. temperature for crystalline fractions of propylene oxide polymers from different catalysts...

To correct for the alkalinity in the sample, place 150 mL of anhydrous methanol into a 500-mL conical flask, add about 50 g of sample, accurately weighed, and swirl to effect solution. Add 1 mL of Indicator, and titrate with 0.1A hydrochloric acid to a yellow endpoint, recording the volume required, in milliliters, as C. Calculate the percent of propylene oxide in thesample taken by the formula... 

Table 5 Changes in Volume of Southern Pine upon Drying and Modification with Propylene Oxide or Acetic Anhydride...

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