With propylene oxide

Styrene is manufactured by alkylating benzene with ethene followed by dehydrogenation, or from petroleum reformate coproduction with propylene oxide. Styrene is used almost exclusively for the manufacture of polymers, of which the most important are polystyrene, ABS plastics and styrene-butadiene rubber. U.S. production 1980 3 megatonnes. 

ARCO has developed a coproduct process which produces KA along with propylene oxide [75-56-9] (95—97). Cyclohexane is oxidized as in the high peroxide process to maximize the quantity of CHHP. The reactor effluent then is concentrated to about 20% CHHP by distilling off unreacted cyclohexane and cosolvent tert-huty alcohol [75-65-0]. This concentrate then is contacted with propylene [115-07-1] in another reactor in which the propylene is epoxidized with CHHP to form propylene oxide and KA. A molybdenum catalyst is employed. The product ratio is about 2.5 kg of KA pet kilogram of propylene oxide. 

The polyalkylene glycol polymer employs a starter that consists of a relatively reactive alcohol and a smaller amount of its potassium or sodium salt. With propylene oxide, for instance, initiation of the polymeri2ation then involves the starter in the following steps ... 

Propylene oxide and other epoxides undergo homopolymerization to form polyethers. In industry the polymerization is started with multihinctional compounds to give a polyether stmcture having hydroxyl end groups. The hydroxyl end groups are utilized in a polyurethane forming reaction. This article is mainly concerned with propylene oxide (PO) and its various homopolymers that are used in the urethane industry. 

CH- CHOHCH3 ), (mono-, di-, and tri-), result from the reaction of ammonia with propylene oxide. Secondary butanolamines,... 

Natural Products. Many natural products, eg, sugars, starches, and cellulose, contain hydroxyl groups that react with propylene oxide. Base-cataly2ed reactions yield propylene glycol monoethers and poly(propylene glycol) ethers (61—64). Reaction with fatty acids results ia a mixture of mono- and diesters (65). Cellulose fibers, eg, cotton (qv), have been treated with propylene oxide (66—68). 

Polyether Polyols. Polyether polyols are addition products derived from cyclic ethers (Table 4). The alkylene oxide polymerisation is usually initiated by alkah hydroxides, especially potassium hydroxide. In the base-catalysed polymerisation of propylene oxide, some rearrangement occurs to give aHyl alcohol. Further reaction of aHyl alcohol with propylene oxide produces a monofunctional alcohol. Therefore, polyether polyols derived from propylene oxide are not truly diftmctional. By using sine hexacyano cobaltate as catalyst, a more diftmctional polyol is obtained (20). Olin has introduced the diftmctional polyether polyols under the trade name POLY-L. Trichlorobutylene oxide-derived polyether polyols are useful as reactive fire retardants. Poly(tetramethylene glycol) (PTMG) is produced in the acid-catalysed homopolymerisation of tetrahydrofuran. Copolymers derived from tetrahydrofuran and ethylene oxide are also produced. 

In addition, polyester polyols are made by the reaction of caprolactone with diols. Poly(caprolactone diols) are used in the manufacture of thermoplastic polyurethane elastomers with improved hydrolytic stabiHty (22). The hydrolytic stabiHty of the poly(caprolactone diol)-derived TPUs is comparable to TPUs based on the more expensive long-chain diol adipates (23). Polyether/polyester polyol hybrids are synthesized from low molecular weight polyester diols, which are extended with propylene oxide. 

The various sources of isobutylene are C streams from fluid catalytic crackers, olefin steam crackers, isobutane dehydrogenation units, and isobutylene produced by Arco as a coproduct with propylene oxide. Isobutylene concentrations (weight basis) are 12 to 15% from fluid catalytic crackers, 45% from olefin steam crackers, 45 to 55% from isobutane dehydrogenation, and high purity isobutylene coproduced with propylene oxide. The etherification unit should be designed for the specific feedstock that will be processed. 

Treatment of (11 aS)-3-isopropyl-11 a-methyl-4-phenyl-1,6,11,11 a-tetrahy-dro[l,4]oxazino[4,3-6]isoquinolin-l-one (243) with 6N HCl in a pressure tube, then the reaction of the work-up residue with propylene oxide gave (3S)-3-methyl-l,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (244) (99S704). 

The initiator usually constitutes less than 1% of the final product, and since starting the process with such a small amount of material in the reaction vessel may be difficult, it is often reacted with propylene oxide to produce a precursor compound, which may be stored until required [6]. The yield of poloxamer is essentially stoichiometric the lengths of the PO and EO blocks are determined by the amount of epoxide fed into the reactor at each stage. Upon completion of the reaction, the mixture is cooled and the alkaline catalyst neutralized. The neutral salt may then be removed or allowed to remain in the product, in which case it is present at a level of 0.5-1.0%. The catalyst may, alternatively, be removed by adsorption on acidic clays or with ion exchangers [7]. Exact maintenance of temperature, pressure, agitation speed, and other parameters are required if the products are to be reproducible, thus poloxamers from different suppliers may exhibit some difference in properties. 

For food and pharmaceutical applications, the microbial count must be reduced to less than 10,000 viable cells per g exopolysaccharide. Treatment with propylene oxide gas has been used for reducing the number of viable cells in xanthan powders. The patented process involves propylene oxide treatment for 3 h in a tumbling reactor. There is an initial evacuation step before propylene oxide exposure. After treatment, evacuation and tumbling are alternated and if necessary the reactor is flushed with sterile nitrogen gas to reduce the residual propylene oxide level below the Food and Drug Administration permitted maximum (300 mg kg 1). The treated polysaccharide is then packaged aseptically. 

Example 4. Glycolysis of Polyurethanes with Propylene Oxide after Pretreatment with a Mixture of Diethanolamine and Potassium Hydroxide.57 Polyurethane scrap was treated with a mixture of diethanolamine and potassium hydroxide at a temperature between about 80 and 140° C with stirring to form an intermediate product. The weight ratio of the scrap PUR polymer to the mixture of diethanolamine and potassium hydroxide was from about 15 1 to 30 1. The intermediate product was reacted with propylene oxide at a temperature of from about 100 to 120°C in a closed reaction vessel to form a polyol. The propylene oxide was added at a rate to maintain a pressure of from about 2 to 5 atm (29-73 psi). The progress of the reaction was followed by following the change of pressure with time. When the pressure remained constant, the reaction of the intermediate product with propylene oxide was considered to be complete. The crude polyol obtained was treated with 10 mol % excess of dodecylbenzene sulfonic acid to remove the potassium hydroxide. 

Example 5. Glycolysis of Polyurethanes with Propylene Oxide after Pretreatment with Ethanolamine.55 A rigid polyurethane foam (ca. 100 g) was dissolved in 30 g ethanolamine by heating. Excess ethanolamine was stripped, leaving a clear solution. Infrared and GPC analysis indicated that the clear solution obtained contained some residual polyurethane, aromatic polyurea, aliphatic polyols, aromatic amines, and N,N -bis(f -hydroxyethyljurea. Next the mixture was dissolved in 45 g propylene oxide and heated at 120°C in an autoclave for 2 h. The pressure increased to 40 psi and then fell to 30 psi at the end of the 2-h heating period. The product was a brown oil with a hydroxyl number of485. 

Thermoplastic xylan derivatives have been prepared by in-hne modification with propylene oxide of the xylan present in the alkaline extract of barley husks [424,425]. Following peracetylation of the hydroxypropylated xylan in formamide solution yielded the water-insoluble acetoxypropyl xylan. The thermal properties of the derivative quahfy this material as a potential biodegradable and thermoplastic additive to melt-processed plastics. Xylan from oat spelts was oxidized to 2,3-dicarboxyhc derivatives in a two-step procedure using HI04/NaC102 as oxidants [426]. 

The hydroxypropyl derivative of guar GaM (HPG) was prepared with propylene oxide in the presence of an alkaline catalyst. HPG was subsequently etherified as such with docosylglycidyl ether in isopropanol and presence of an alkaline catalyst [432]. The peculiar features of the long-chain hydrophobic derivatives were ascribed to a balance between inter- and intramolecular interactions, which is mainly governed by the local stress field. 

Shah et al. (1994) have studied the preparation of a class of compounds called Indans, by cross-dimerization of AMS with amylenes, using an ion-exchange resin and acid-treated clay catalysts (Eqns. (12) and (13)). Indans can be subsequently converted, e.g. by acetylation, into perfumric compounds having mu.sk odour. For example, 1,1,2,3,3-pentamethylindan, the product obtained by cross-dimerization of AMS and wo-amylene (Eqn. (12)), can be reacted with propylene oxide and /7 ra-formaldehyde to give an indan type isochroman musk compound, 6-oxa-l,l,2,3,3,8-hexamethyl-2,3,5,6,7,8-hexahydro-lH-benz(f)-indene, sold as Galaxolide commercially. 

In the first step 2,6-xylenol is condensed with propylene oxide in the presence of NaOH at elevated temperature and pressure yielding I-(2,6-dimethyl)-phenoxy-propanoI-2 (DMFP). In the second step, ammonia is reacted with DMFP in the gas phase in the presence of hydrogen and a solid catalyst at a temperature of 450-475 K under atmospheric pressure. The product, l-(2,6-dimethyl)-phenoxy-2-aminopropane (DMFAP) is isolated from the condensed reaction mixture and purified as its hydrochloride. 

An amido-amine (e.g., from the reaction of tetraethylenepentamine with stearic acid) is modified with propylene oxide [792]. The product is dispersed in a polymer matrix such as an acrylic or methacrylic polymer. The inhibitor is slowly released into the surrounding environment, such as in an oil or gas well, to prevent corrosion of metal equipment in the well. 

The blend is partially crosslinked with a vinyl monomer when dissolved in an organic aprotic solvent and has a pH of 5.0 or lower. The first block copolymer is prepared by polycondensing a bis-hydroxyalkyl ether, such as dipropylene glycol, diethylene glycol, and the like, with propylene oxide. Next, the resulting propoxylated diol is reacted with ethylene oxide to produce the block copolymer. The second copolymer is prepared by polycondensing 2-amino-2-hydroxymethyl-1,3-propanediol, commonly known as TRIS, with... 

Figure 5 Surface pressure(mN/m) dependence on time(hrs.), of aqueous poly(oxyethylene) copolymers M = 103 with propylene oxide (POEOP-7.7 mole %) 0 5ppm ...

Freshly distilled propanal (4.4 g, 0.075 mol) was added at room temperature over a period of 20 min to a stirred mixture of benzyl carbamate (7.55 g, 0.05 mol), phenyldichlorophosphine (8.95 g, 0.05 mol), and glacial acetic acid (10 ml). The mixture was refluxed for 40 min, treated with 4 N hydrochloric acid (50 ml), and then refluxed again for 30 min. After cooling, the organic layer was removed, and the aqueous layer was boiled with charcoal (2 g) and evaporated to dryness in vacuum. The residue was dissolved in methanol (40 ml) and treated with propylene oxide until a pH of 6 to 7 was attained. The resultant precipitate was filtered, washed with acetone, and crystallized from methanol/water to give pure (l-aminopropyl)phenylphos-phinic acid (4.08 g, 41%) of mp 256-258°C. 

Progressive Infiltration with Propylene Oxide Polybed 2 1 Propylene oxide Polybed, 1 hr 1 1 Propylene oxide Polybed, 1 hr 1 2 Propylene oxide Polybed, 1 hr (Polybed formulation procedures accompany commercially available polybed kits.)... 

Dehydrate through an ethanol series substituted with propylene oxide and add several drops of Epon before sections dry. 

The manufacture of a polyol lubricant by the condensation of an alcohol with propylene oxide in a semi-batch reactor proceeds according to the following reaction... 

Journal of Coatings Technology 72, No. 905, June 2000, p.67-72 FORMULATING WATER-BASED SYSTEMS WITH PROPYLENE-OXIDE-BASED GLYCOL ETHERS... 

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. 

---